--- doc/gutshtml/SessionOn2.html 2002/06/28 20:30:29 1.1 +++ doc/gutshtml/SessionOn2.html 2003/07/22 14:47:00 1.2 @@ -1,1670 +1,3340 @@ - - - - - -Session One: Problem Engine/Special Targets (grade, edit, print) (Guy) - - - -
-

Session One: Problem Engine/Special Targets (grade, edit, print) (Guy)

-

Tags

- -

Arguments for all response tags

- -

Implemented response tags

- -

o      - <externalresponse> implements the ability to have an external program grade a response, - expects either a <textline> or <textfield> inside the tag.

-

Arguments:

- -

The response of the remote server needs to be in XML as follows.

- 
 <loncapagrade>     <awardetail> CORRECT     </awardetail>     <message> A message to be shown to the students     </message> </loncapagrade>            
- - -

All tags that implement a foil structure have an optional arg of max - that controls the maximum number of total foils to show.

- -

All of these tags must appear inside a <*response> tag.

- -

This group of tags implement a mechanism for getting data for students, they - will usually be used by a <*response>.

- -

This group of tags generate useful pieces of output.

- - 
  <randomlabel bgimg="URL" width="12" height="45" texwidth="50">     <labelgroup name="GroupOne" type="image">       <location x="123" y="456" value="10" />       <location x="321" y="654" value="20" />       <location x="213" y="546" value="13" />       <label description="TEXT-1">IMG-URL</label>       <label description="TEXT-2">IMG-URL</label>       <label description="TEXT-3">IMG-URL</label>     </labelgroup>     <labelgroup name="GroupTwo" type="text">       <location x="12" y="45" />       <location x="32" y="65" />       <location x="21" y="54" />       <label>TEXT-1</label>       <label>TEXT-2</label>       <label>TEXT-3</label>     </labelgroup>    </randomlabel>         
-

Arguments:

- -

Internal tags:

- -

These tags allow the document to behave programatically

- -

These tags give the problem a structure and take care of the recording of - data and giving the student messages.

- -

<script> Functions

-

A list of functions that have been written that are available in the Safe - space scripting environment inside a problem.

- -

Detailed descriptions of each function and comparison - with CAPA

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

CAPA Functions

LON-CAPA

Descriptions

Differences (if any)

sin(x), cos(x), tan(x)

&sin($x), &cos($x), - &tan($x)

Trigonometric functions where - x is in radians. $x can be a pure number, i.e., you can call &sin(3.1415)

 

asin(x), acos(x), atan(x), atan2(y,x)

&asin($x), &acos($x), - &atan($x), &atan2($y,$x)

Inverse trigonometric functions. - Return value is in radians. For asin and acos the value of x must be - between -1 and 1. The atan2 returns a value between -pi and pi the sign - of which is determined by y. $x and $y can be pure numbers

 

log(x), log10(x)

&log($x), &log10($x)

Natural and base-10 logarithm. - $x can be a pure number

 

exp(x), pow(x,y), sqrt(x)

&exp($x), &pow($x,$y), - &sqrt($x)

Exponential, power and square - root, i.e.,ex, xy and /x. $x and $y can be pure - numbers

 

abs(x), sgn(x)

&abs($x), &sgn($x)

Abs takes the absolute value - of x while sgn(x) returns 1, 0 or -1 depending on the value of x. For - x>0, sgn(x) = 1, for x=0, sgn(x) = 0 and for x<0, sgn(x) = -1. - $x can be a pure number

 

erf(x), erfc(x)

&erf($x), &erfc($x)

Error function.  erf = - 2/sqrt(pi) integral (0,x) et-sq and erfx(x) - = 1.0 - erf(x).  $x can be a pure number

 

ceil(x), floor(x)

&ceil($x), &floor($x)

Ceil function returns an integer - rounded up whereas floor function returns and integer rounded down. - If x is an integer than it returns the value of the integer. $x can - be a pure number

 

min(...), max(...)

&min(...), &max(...)

Returns the minimum/ maximum - value of a list of arguments if the arguments are numbers. If the arguments - are strings then it returns a string sorted according to the ASCII codes

 

factorial(n)

&factorial($n)

Argument (n) must be an integer - else it will round down. The largest value for n is 170. $n can be a - pure number

 

N%M

$N%$M

N and M are integers and returns - the remainder (in integer) of N/M. $N and $M can be pure numbers

 

sinh(x), cosh(x), tanh(x)

&sinh($x), &cosh($x), - &tanh($x)

Hyperbolic functions. $x can - be a pure number

 

asinh(x), acosh(x), atanh(x)

&asinh($x), &acosh($x), - &atanh($x)

Inverse hyperbolic functions. - $x can be a pure number

 

/DIS($x,"nn")

&format($x,"nn")

Display or format $x as nn where - nn is nF or nE and n is an integer.

 The difference is obvious.

Not in CAPA

&prettyprint($x,"nn")

Display or format $x as nn where - nn is nF or nE and n is an integer. In E mode it will attempt to generate - a pretty x10^3 rather than a E3 following the number

 

roundto(x,n)

&roundto($x,$n)

Rounds a real number to n decimal - points. $x and $n can be pure numbers

 

web("a","b","c") - or web(a,b,c)

&web("a","b","c") - or &web($a,$b,$c)

Returns either a, b or c depending - on the output medium. a is for plain ASCII, b for tex output and c for - html output

 

html("a") or html(a)

&html("a") or - &html($a)

Output only if the output mode - chosen is in html format

 

jn(m,x)

&j0($x), &j1($x), &jn($m,$x), - &jv($y,$x)

Bessel functions of the first - kind with orders 0, 1 and m respectively. For jn(m,x), m must be an - integer whereas for jv(y,x), y is real. $x can be a pure number. $m - must be an integer and can be a pure integer number. $y can be a pure - real number

In CAPA, j0, j1 and jn are contained - in one function, jn(m,x) where m takes the value of 0, 1 or 2. jv(y,x) - is new to LON-CAPA.

yn(m,x)

&y0($x), &y1($x), &yn($m,$x), - &yv($y,$x)

Bessel functions of the second - kind with orders 0, 1 and m respectively. For yn(m,x), m must be an - integer whereas for yv(y,x), y is real. $x can be a pure number. $m - must be an integer and can be a pure integer number. $y can be a pure - real number

In CAPA, y0, y1 and yn are contained - in one function, yn(m,x) where m takes the value of 0, 1 or 2. yv(y,x) - is new to LON-CAPA.

random(l,u,d)

&random($l,$u,$d)

Returns a uniformly distributed - random number between the lower bound, l and upper bound, u in steps - of d. $l, $u and $d can be pure numbers

In CAPA, all the 3 arguments - must be of the same type. However, now you can mix the type

choose(i,...)

&choose($i,...)

Choose the ith item from the - argument list. i must be an integer greater than 0 and the value of - i should not exceed the number of items. $i can be a pure integer

 

/MAP(seed;w,x,y,z;a,b,c,d)

Option 1 - &map($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) - or
- Option 2 - &map($seed,\@mappedArray,[$a,$b,$c,$d])
- Option 3 - @mappedArray = &map($seed,[$a,$b,$c,$d])
- Option 4 - ($w,$x,$y,$z) = &map($seed,\@a)
- where $a='A'
- $b='B'
- $c='B'
- $d='B'
- $w, $x, $y, and $z are variables

Assigns to the variables $w, - $x, $y and $z the values of the $a, $b, $c and $c (A, B, C and D). The - precise value for $w .. depends on the seed. (Option 1 of calling map). - In option 2, the values of $a, $b .. are mapped into the array, @mappedArray. - The two options illustrate the different grouping. Options 3 and 4 give - a consistent way (with other functions) of mapping the items. For each - option, the group can be passed as an array, for example, [$a,$b,$c,$d] - => \@a.

In CAPA, the arguments are divided - into three groups separated by a semicolon ;. In LON-CAPA, the separation - is done by using [] brackets or using an array @a. Note the backslash - (\) before the arguments in the second and third groups.

rmap(seed;a,b,c,d;w,x,y,z)

Option 1 - &rmap($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) - or
- Option 2 - &rmap($seed,\@rmappedArray,[$a,$b,$c,$d])
- Option 3 - @rmapped_array = &rmap($seed,[$a,$b,$c,$d])
- Option 4 - ($w,$x,$y,$z) = &rmap($seed,\@a)
- where $a='A'
- $b='B'
- $c='B'
- $d='B'
- $w, $x, $y, and $z are variables

The rmap functions does the - reverse action of map if the same seed is used in calling map and rmap. -

In CAPA, the arguments are divided - into three groups separated by a semicolon ;. In LON-CAPA, the separation - is done by using [] brackets (with create an unamed vector reference) - or using an array @a. Note the backslash (\) before the arguments in - the second and third groups (Which cause Perl to send to variable locations - rather than the variable values, similar to a C pointer).

NOT IMPLEMENTED IN CAPA

$a=&xmlparse($string)

Runs the internal parser over - the argument parsing for display. Warning - This will result in different strings in different targets. Don't use - the results of this function as an answer.

New to LON-CAPA

tex(a,b), tex("a","b")

&tex($a,$b), &tex("a","b")

Returns a if the output mode - is in tex otherwise returns b

 

var_in_tex(a)

&var_in_tex($a)

Equivalent to tex("a","")

 

to_string(x), to_string(x,y)

&to_string($x), &to_string($x,$y)

If x is an integer, returns - a string. If x is real than the output is a string with format given - by y. For example, if x = 12.3456, &to_string(x,".3F") - = 12.345 and &to_string(x,".3E") = 1.234E+01.

 

capa_id(), class(), section(), - set(), problem()

&class(), &section()

Returns null string, class descriptive - name, section number, set number and null string.

capa_id(), set() and problem() - are no longer used. Currently, they return a null value.

name(), student_number()

&name(), &student_number()

Return the full name in the - following format: lastname, firstname initial. Student_number returns - the student 9-alphanumeric string. If undefined, the functions return - null.

 

open_date(), due_date(), answer_date()

&open_date(), &due_date(), - &answer_date()

Problem open date, due date - and answer date. The time is also included in 24-hr format.

Output format for time is changed - slightly. If pass noon, it displays ..pm else it displays ..am. So 23:59 - is displayed as 11:59 pm.

get_seed(), set_seed()

Not implemented

Get and set the random seed.

 

sub_string(a,b,c)

&sub_string($a,$b,$c)
- perl  substr function. However, note the differences

Retrieve a portion of string - a starting from b and length c. For example,  $a = "Welcome - to LON-CAPA"; $result=&sub_string($a,4,4); then $result is - "come"

Perl intrinsic function, substr(string,b,c) - starts counting from 0 (as opposed to 1). In the example to the left, - substr($a,4,4) returns "ome ".

array[xx]

@arrayname
- Array is intrinsic in perl. To access a specific element use $arrayname[$n] - where $n is the $n+1 element since the array count starts from 0

"xx" can be a variable - or a calculation.

In LON-CAPA, an array is defined - by @arrayname. It is not necessary to specify the dimension of the array. 

array_moments(B,A)

@B=&array_moments(@A)

Evaluates the moments of an - array A and place the result in array B[i] where i = 0 to 4. The contents - of B are as follows: B[0] = number of elements, B[1] = mean, B[2] = - variance, B[3] = skewness and B[4] = kurtosis.

In CAPA, the moments are passed - as an array in the first argument whereas in LON-CAPA, the array containing - the moments are set equal to the function.

array_max(Name), array_min(Name)

&min(@Name), &max(@Name)

In LON-CAPA to find the maximum - value of an array, use &max(@arrayname)  and to find the minimum - value of an array, use &min(@arrayname)

Combined with the min and max - functions defined earlier.

init_array(Name)

undef @name

To destroy the contents of an - array, use

Use perl intrinsic undef function.

random_normal (return_array,item_cnt,seed,av,std_dev)

@return_array=&random_normal - ($item_cnt,$seed,$av,$std_dev)

Generate $item_cnt deviates - of normal distribution of average $av and standard deviation $std_dev. - The distribution is generated from seed $seed

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_beta (return_array,item_cnt,seed,aa,bb)

@return_array=&random_beta - ($item_cnt,$seed,$aa,$bb)
- NOTE: Both $aa and $bb MUST be greater than 1.0E-37.

Generate $item_cnt deviates - of beta distribution. The density of beta is: X^($aa-1) *(1-X)^($bb-1) - /B($aa,$bb) for 0<X<1.

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_gamma (return_array,item_cnt,seed,a,r)

@return_array=&random_gamma - ($item_cnt,$seed,$a,$r)
- NOTE: Both $a and $r MUST be positive.

Generate $item_cnt deviates - of gamma distribution. The density of gamma is: ($a**$r)/gamma($r) * - X**($r-1) * exp(-$a*X).

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_exponential (return_array,item_cnt,seed,av)

@return_array=&random_exponential - ($item_cnt,$seed,$av)
- NOTE: $av MUST be non-negative.

Generate $item_cnt deviates - of exponential distribution.

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_poisson (return_array,item_cnt,seed,mu)

@return_array=&random_poisson - ($item_cnt,$seed,$mu)
- NOTE: $mu MUST be non-negative.

Generate $item_cnt deviates - of poisson distribution.

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_chi (return_array,item_cnt,seed,df)

@return_array=&random_chi - ($item_cnt,$seed,$df)
- NOTE: $df MUST be positive.

Generate $item_cnt deviates - of chi_square distribution with $df degrees of freedom.

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

random_noncentral_chi (return_array,item_cnt,seed,df,nonc)

@return_array=&random_noncentral_chi - ($item_cnt,$seed,$df,$nonc)
- NOTE: $df MUST be at least 1 and $nonc MUST be non-negative.

Generate $item_cnt deviates - of noncentral_chi_square distribution with $df degrees of freedom and - noncentrality parameter $nonc.

In CAPA the results are passed - as the first argument whereas in LON-CAPA the results are set equal - to the function.

NOT IMPLEMENTED IN CAPA

@return_array=&random_f - ($item_cnt,$seed,$dfn,$dfd)
- NOTE: Both $dfn and $dfd MUST be positive.

Generate $item_cnt deviates - of F (variance ratio) distribution with degrees of freedom $dfn (numerator) - and $dfd (denominator).

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_noncentral_f - ($item_cnt,$seed,$dfn,$dfd,$nonc)
- NOTE: $dfn must be at least 1, $dfd MUST be positive, and $nonc must - be non-negative.

Generate $item_cnt deviates - of noncentral F (variance ratio) distribution with degrees of freedom - $dfn (numerator) and $dfd (denominator). $nonc is the noncentrality - parameter.

New to LON-CAPA

NOT DOCUMENTED IN CAPA

@return_array=&random_multivariate_normal - ($item_cnt,$seed,\@mean,\@covar)
- NOTE: @mean should be of length p array of real numbers. @covar should - be a length p array of references to length p arrays of real numbers - (i.e. a p by p matrix.

Generate $item_cnt deviates - of multivariate_normal distribution with mean vector @mean and variance-covariance - matrix.

Note the backslash before the - @mean and @covar arrays.

NOT IMPLEMENTED IN CAPA

@return_array=&random_multinomial - ($item_cnt,$seed,@p)
- NOTE: $item_cnt is rounded with int() and the result must be non-negative. - The number of elements in @p must be at least 2.

Returns single observation from - multinomial distribution with $item_cnt events classified into as many - categories as the length of @p. The probability of an event being classified - into category i is given by ith element of @p. The observation is an - array with length equal to @p, so when called in a scalar context it - returns the length of @p. The sum of the elements of the obervation - is equal to $item_cnt.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_permutation - ($item_cnt,@array)

Returns @array randomly permuted.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_uniform - ($item_cnt,$seed,$low,$high)
- NOTE: $low must be less than or equal to $high.

Generate $item_cnt deviates - from a uniform distribution.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_uniform_integer - ($item_cnt,$seed,$low,$high)
- NOTE: $low and $high are both passed through int(). $low must be less - than or equal to $high.

Generate $item_cnt deviates - from a uniform distribution in integers.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_binomial - ($item_cnt,$seed,$nt,$p)
- NOTE: $nt is rounded using int() and the result must be non-negative. - $p must be between 0 and 1 inclusive.

Generate $item_cnt deviates - from the binomial distribution with $nt trials and the probabilty of - an event in each trial is $p.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_negative_binomial - ($item_cnt,$seed,$ne,$p)
- NOTE: $ne is rounded using int() and the result must be positive. $p - must be between 0 and 1 exclusive.

Generate an array of $item_cnt - outcomes generated from negative binomial distribution with $ne events - and the probabilty of an event in each trial is $p.

New to LON-CAPA

-

<script> Variables

- -

Form internals

-

Form elements used for homework editing/response

-

the form is named lonhomework

-

Viewing a problem (either CSTR or RES space)

- -

Editing a problem (Edit mode)

-

tagdepth referes to the current value of the xmlparsers tagdepth couter ($Apache::lonxml::currentdepth)

-

Note: the file edit.pm has many helper functions for creating the standard - elements for editing a tag and it's attributes, all of those functions follow - these conventions

- - -

Symbs

-

To identify a specific instance of a resource, LON-CAPA uses symbols or Ňsymbs.Ó - These identifiers are built from the URL of the map, the resource number of - the resource in the map, and the URL of the resource itself. The latter is - somewhat redundant, but might help if maps change.

-

An example is

-

 msu/korte/parts/part1.sequence___19___msu/korte/tests/part12.problem

-

The respective map entry is

-

 <resource - id="19" src="/res/msu/korte/tests/part12.problem"     -

-

  title="Problem - 2">

-

 </resource>

-

Symbs are used by the random number generator, as well as - to store and restore data specific to a certain instance of for example a - problem.

-

Store / Restore

-

2 important functions in lonnet.pm are &Apache::lonnet::cstore() and &Apache::lonnet:restore() (and - &Apache::lonnet::store(), which is is the non-critical message twin of cstore). These functions are for handlers to store a perl hash to - a userŐs permanent data space in an easy manner, and to retrieve it again - on another call. It is expected that a handler would use this once at the - beginning to retrieve data, and then again once at the end to send only the - new data back.

-

The data is stored in the userŐs data directory - on the userŐs homeserver under the ID of the course.

-

The hash that is returned by restore will have all of the previous value for all of the elements - of the hash.

-

Example:

-

#creating a hash

-

my %hash;

-

$hash{'foo'}='bar';

-

#storing it

-

&Apache::lonnet::cstore(\%hash);

-

#changing a value

-

$hash{'foo'}='notbar';

-

#adding a new value

-

$hash{'bar'}='foo';

-

&Apache::lonnet::cstore(\%hash);

-

#retrieving the hash

-

my %history=&Apache::lonnet::restore();

-

#print the hash

-

foreach my $key (sort(keys(%history))) - {

-

    print("\%history{$key} - = $history{$key}");

-

}

-

Will print out:

-

%history{1:foo} = bar

-

%history{1:keys} = foo:timestamp

-

%history{1:timestamp} - = 990455579

-

%history{2:bar} = foo

-

%history{2:foo} = notbar

-

%history{2:keys} = foo:bar:timestamp

-

%history{2:timestamp} - = 990455580

-

%history{bar} = foo

-

%history{foo} = notbar

-

%history{timestamp} = - 990455580

-

%history{version} = 2

-

Note that the special hash entries keys, - version and timestamp were - added to the hash. version will be - equal to the total number of versions of the data that have been stored. The - timestamp attribute will be the UNIX time the hash was stored. keys is available in every historical section to list which keys - were added or changed at a specific historical revision of a hash.

-

Warning do not store the hash that restore returns directly. This - will cause a mess since it will restore the historical keys as if the were - new keys. I.E. 1:foo will become 1:1:foo etc.

-

Calling convention:

-

  my %record=&Apache::lonnet::restore($symb,$courseid,$domain,$uname,$home);

-

  &Apache::lonnet::cstore(\%newrecord,$symb,$courseid,$domain,$uname,$home);

-

Arguments (only %newrecord is required the rest - are somewhat optional, read the details):

-

á      - $symb - a string containing the internal name of the specific instance - of a resource. Usually this value can be gotten from &Apache::lonnet::symbread($filename). If the argument is blank, it will attempt to use symbread() for it. If the result is ambiguous store/restore will fail. -

-

á      - $courseid - the internal name for a course, usually found in $ENV{'request.course.id'} which is what will be looked at if no value is passed to - the functions.

-

á      - $domain - the domain that the user belongs to, usually found in $ENV{'user.domain'} which is what will be looked at if no value is passed to - the functions.

-

á      - $uname - the login name for the user, usually found in $ENV{'user.name'} which is what will be looked at if no value is passed to - the functions.

-

á      - $home - the homeserver for the user, usually found in $ENV{'user.home'} but can be easily gotten from a domain and name through &Apache::lonnet::homeserver($uname,$domain). If no value is passed to store/restore the value in %ENV - will be used.

-

á      - %newrecord - the hash to store being passed by reference

-

Return values:

-

á      - an empty string - the function was unable to determine exactly where to store - or restore from. At least one of the "optional" arguments was unable - to be determined.

-

á      - a hash - restore successfully read a old hash for this specific - user / resource instance.

-

á      - no_such_host - the $home specfied - desn't exist in the network.

-

á      - con_delayed - the $home was uncontactable - at this time. The store will be delayed until it is again available.

-

á      - con_failed - the $home was uncontactable - at this time and store was unable to delay the store until a later time. The - store failed.

-

á      - ok - the store completed succesfully

-

á      - error: - remote server failied to store or restore the reason follows - the :

-

Mandatory Homework Data

- 
 
- 
<Provided by &EXT() and set external to the resource, required>
- 
resource.partid.opendate   #unix time of when the local machine should let the
- 
                           #student in
- 
 
- 
resource.partid.duedate    #unix time of when the local machine should stop
- 
                           #accepting answers
- 
 
- 
resource.partid.answerdate #unix time of when the local machine should
- 
                           #provide the correct answer to the student
- 
 
- 
resource.partid.weight     # points the problem is worth
- 
 
- 
resource.partid.maxtries   # maximum number of attempts the student can have
- 
 
- 
resource.partid.type       # type of problem homework can be:
- 
                           # homework - randomized, graded, stored with
- 
                           #            requesting user, full feeback
- 
                           # exam - randomized, graded, stored with
- 
                           #        requesting user, minimal feedback
- 
                           # form - unrandomized, ungraded, stored with
- 
                           #        specified user, full feedback
- 
                           # survey - unrandomized, ungraded, stored with
- 
                           #          requesting user, full feedback
- 
 
- 
 
- 
 
- 
<numerical/formula/response needed: (has a default if nonexistant)>
- 
 
- 
resource.partid.responseid.tol   # lots of possibilities here
- 
                    # percentage, range (inclusive and exclusive),
- 
                     # variable name, etc
- 
                    # 3%
- 
                    # 0.5
- 
                    # .05+
- 
                    # 3%+
- 
                    # 0.5+,.005
- 
 
- 
resource.partid.responseid.sig  # one or two comma sepearted integers,   
- 
                                # specifying the number of significatn figures
- 
                                # a student must use
- 
 
- 
 
- 
 
- 
<Problem sets using cstore (required):>
- 
resource.partid.solved # if not set, problem yet to be viewed
- 
                # incorrect_attempted == incorrect and attempted
- 
                # correct_by_student == correct by student work
- 
                # correct_by_override == correct, instructor override
- 
                # incorrect_by_override == incorrect, instructor override
- 
                # excused == excused, problem no longer counts for student
- 
                # '' (empty) == not attempted
- 
                # ungraded_attempted == an ungraded answer has been
- 
                                          sumbitted and stored
- 
resource.partid.tries  # positive integer of number of unsuccessful attempts
- 
                # made, malformed answers don't count if feedback is
- 
                # on
- 
 
- 
resource.partid.awarded # float between 0 and 1, percentage of
- 
                 # resource.weight that the stundent earned.
- 
 
- 
resource.partid.award # final detailed award that was applied to the entire
- 
                      # part of the question, check awarddetail below for
- 
                      # possibilities
- 
 
- 
resource.partid.previous # boolean, is this submission a previous submission
- 
 
- 
resource.partid.responseid.submissons
- 
                    # the student submitted string for the part.response
- 
 
- 
resource.partid.responseid.awarddetail
- 
                     # list of all of the results of grading the submissions
- 
                     # in detailed form of the specific failure
- 
                      #Possible values:
- 
                     # EXACT_ANS, APPROX_ANS : student is correct
- 
                     # NO_RESPONSE : student submitted no response
- 
                     # MISSING_ANSWER : student submitted some but not
- 
                     #                   all parts of a response
- 
                     # WANTED_NUMERIC : expected a numeric answer and
- 
                     #                   didn't get one
- 
                      # SIG_FAIL : incorrect number of Significant Figures
- 
                     # UNIT_FAIL : incorrect unit
- 
                     # UNIT_NOTNEEDED : Submitted a unit when one shouldn't
- 
                     # NO_UNIT : needed a unit but none was submitted
- 
                      # BAD_FORMULA : syntax error in submitted formula
- 
                     # INCORRECT : answer was wrong
- 
                     # SUBMITTED : submission wasn't graded
- 
                     # ERROR : unable to get a grade
- 
 
- 
resource.partid.responseid.message (optional) (not yet supported)
- 
                       # a message that should be shown to the student
- 
 
- 
resource.partid.bonustries (optional) (not yet supported)
- 
                     # if set, added to the maxtries parameter for student
- 
                     # total number of tries overall
- 
 
-

Sample Problems

-

A Simple Problem

-

<problem>

-

        - <script type="loncapa/perl">

-

$length=&random(10,99,.1);

-

$width=&random(1,10,.01);

-

@area=($length*($width*10));

-

        - </script>

-

What - is the area of a box $length mm in length and

-

&format($width,"2E") - cm in width.

-

        - <numericalresponse id="11" answer="@area" units="mm^2">

-

                - <textline></textline>

-

                - <responseparam name="tol" type="tolerance" default="5%"></responseparam>

-

        - </numericalresponse>

-

</problem>

-

A More Complex Problem

-

<problem>

-

<displayduedate - />

-

<p><displaytitle - /></p>

-

<script type="loncapa/perl">

-

$vF="<b> - F<sub>1</sub> </b>";

-

$vF1="<b> - F<sub>1</sub> </b>";

-

$vF2="<b> - F<sub>2</sub> </b>";

-

$mF="|<b>F</b>|";

-

$F1mag="|<b>F<sub>1</sub></b>|";

-

$F2mag="|<b>F<sub>2</sub></b>|";

-

$trq1mag="|<b> - <font face=symbol>t</font><sub>1</sub></b>|";

-

$trq2mag="|<b> - <font face=symbol>t</font><sub>2</sub></b>|";

-

$Q1="Q<sub>1</sub>";

-

$Q2="Q<sub>2</sub>";

-

$tau="<font - face=symbol>t</font>";

-

$tau1="<font - face=symbol><b>t</b></font><sub>1</sub>";

-

   $val=&random(1,4,1);

-

   $tp=&choose($val,"her","her","his","his");

-

   $sd=&choose($val,"daughter","niece","nephew","son");

-

</script>

-

<startouttext - />

-

$trq1mag and $trq2mag - are the magnitudes of the torques produced repectively by

-

forces $vF1 and $vF2 - with respect the pivot P. The magnitudes of $vF1 is

-

$F1mag and that of - $vF2 is $F2mag. $Q1 and $Q2 are the locations

-

on a rigid body where - $vF1 and $vF2 act. 

-

<endouttext />

-

<optionresponse - max="600">

-

        - <foilgroup options="('Correct','Incorrect','Can not tell')">

-

                - <conceptgroup concept="Effect of the moment-arm on the torque">

-

                        - <foil name="1a" value="Incorrect">

-

                          - For $F1mag larger than $F2mag , $trq1mag is larger than $trq2mag

-

                        - </foil>

-

                        - <foil name="1b" value="Incorrect">

-

                          - For $F1mag smaller than $F2mag , $trq1mag is smaller than $trq2mag

-

                        - </foil>

-

           -              <foil - name="1c" value="Correct">

-

                          - For $F1mag larger than $F2mag , $trq1mag can be less  than $trq2mag

-

                        - </foil>

-

                        - <foil name="1d" value="Correct">

-

                          - For $F1mag smaller than $F2mag , $trq1mag can be larger  than $trq2mag

-

                        - </foil>

-

                - </conceptgroup>

-

                - <conceptgroup concept="For a given pivot, relation of force vector - to torque.">

-

                        - <foil name="2a" value="Correct">

-

                  - The moment-arm of $vF is the shortest distance from P to the line along $vF - .

-

                        - </foil>

-

                        - <foil name="2b" value="Incorrect">

-

                          - The moment-arm of $vF is the shortest distance from P to $vF vector.

-

                        - </foil>

-

                        - <foil name="2c" value="Correct">

-

                          - The moment-arm of $vF is not the distance from P to Q<sub>1</sub>.

-

                -         </foil>

-

                        - <foil name="2d" value="Incorrect">

-

                          - The moment-arm of $vF is the distance from P to Q<sub>1</sub>.

-

                        - </foil>

-

                - </conceptgroup>

-

                - <conceptgroup concept="Torque is force x moment-arm.">

-

                        - <foil name="3a" value="Correct">

-

                          - $trq1mag equals to the product of the moment-arm and $F1mag .

-

                      - </foil>

-

                        - <foil name="3b" value="Incorrect">

-

                        - $trq1mag equals to $F1mag times the distance from Q<sub>1</sub> - to P.

-

                        - </foil>

-

                        - <foil name="3c" value="Correct">

-

                          - $trq1mag is not equal to the product of $F1mag and the distance from Q<sub>1</sub> - to P.

-

                        - </foil>

-

                        - <foil name="3d" value="Incorrect">

-

                        - $trq1mag is not equal to the product of the moment-arm and $F1mag .

-

         -                </foil>

-

                - </conceptgroup>

-

                - <conceptgroup concept="Pivot point is required to calculate torque">

-

                        - <foil name="4a" value="Correct">

-

                         - $tau1 vector depends on the location of P.

-

                        - </foil>

-

                        - <foil name="4b" value="Incorrect">

-

                         - $tau1 vector does not depend on the location of P.

-

                        - </foil>

-

                        - <foil name="4c" value="Correct">

-

                         - $tau1 vector has no meaning unless a pivot is selected.

-

                        - </foil>

-

                        - <foil name="4d" value="Incorrect">

-

                         - $tau1 vector can be determined without selecting P.

-

                        - </foil>

-

                - </conceptgroup>

-

                - <conceptgroup concept="torque from 2 forces acting along same line">

-

                        - <foil name="5a" value="Correct">

-

                          - Two equal forces, acting on a body along the same line but at different positions, - produce equal torques with respect to a given pivot."

-

                        - </foil>

-

                        - <foil name="5b" value="Incorrect">

-

                          - Two equal forces, along the same line, produce equal torques with respect - to a given pivot only if they act at the same point on a body."

-

                        - </foil>

-

                        - <foil name="5c" value="Incorrect">

-

                          - Two equal forces acting on a body along the same line but at different positions, - produce equal torques for only one pivot."

-

                        - </foil>

-

                - </conceptgroup>

-

                - <foil name="6" value="unused">

-

                        - This foil will never display since it is unused.

-

                - </foil>

-

        - </foilgroup>

-

        - <notsolved>

-

                - <hintgroup>

-

Think the definition - of the torque. The force and the moment-arm respect to the pivot. 

-

                - </hintgroup>

-

      -   </notsolved>

-

</optionresponse>

-

</problem>

-

 

-

-

Fig. 3.1.1 Đ Internal Structure of Homework Handler

-
-
-
- - + + + + + + + + + + +Session One: Problem Engine/Special Targets (grade, edit, print) (Guy) + + + + + + + +
+ +

Session One: Problem Engine/Special Targets (grade, edit, print) (Guy)

+ +

Tags

+ + + +

Arguments for all response tags

+ + + +

Implemented response tags

+ + + +

o      + + <externalresponse> implements the ability to have an external program grade a response, + + expects either a <textline> or <textfield> inside the tag.

+ +

Arguments:

+ + + +

The response of the remote server needs to be in XML as follows.

+ + 
 <loncapagrade>     <awardetail> CORRECT     </awardetail>     <message> A message to be shown to the students     </message> </loncapagrade>            
+ + + + + +

All tags that implement a foil structure have an optional arg of max + + that controls the maximum number of total foils to show.

+ + + +

All of these tags must appear inside a <*response> tag.

+ + + +

This group of tags implement a mechanism for getting data for students, they + + will usually be used by a <*response>.

+ + + +

This group of tags generate useful pieces of output.

+ + + + 
  <randomlabel bgimg="URL" width="12" height="45" texwidth="50">     <labelgroup name="GroupOne" type="image">       <location x="123" y="456" value="10" />       <location x="321" y="654" value="20" />       <location x="213" y="546" value="13" />       <label description="TEXT-1">IMG-URL</label>       <label description="TEXT-2">IMG-URL</label>       <label description="TEXT-3">IMG-URL</label>     </labelgroup>     <labelgroup name="GroupTwo" type="text">       <location x="12" y="45" />       <location x="32" y="65" />       <location x="21" y="54" />       <label>TEXT-1</label>       <label>TEXT-2</label>       <label>TEXT-3</label>     </labelgroup>    </randomlabel>         
+ +

Arguments:

+ + + +

Internal tags:

+ + + +

These tags allow the document to behave programatically

+ + + +

These tags give the problem a structure and take care of the recording of + + data and giving the student messages.

+ + + +

<script> Functions

+ +

A list of functions that have been written that are available in the Safe + + space scripting environment inside a problem.

+ + + +

Detailed descriptions of each function and comparison + + with CAPA

+ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +

CAPA Functions

LON-CAPA

Descriptions

Differences (if any)

sin(x), cos(x), tan(x)

&sin($x), &cos($x), + + &tan($x)

Trigonometric functions where + + x is in radians. $x can be a pure number, i.e., you can call &sin(3.1415)

 

asin(x), acos(x), atan(x), atan2(y,x)

&asin($x), &acos($x), + + &atan($x), &atan2($y,$x)

Inverse trigonometric functions. + + Return value is in radians. For asin and acos the value of x must be + + between -1 and 1. The atan2 returns a value between -pi and pi the sign + + of which is determined by y. $x and $y can be pure numbers

 

log(x), log10(x)

&log($x), &log10($x)

Natural and base-10 logarithm. + + $x can be a pure number

 

exp(x), pow(x,y), sqrt(x)

&exp($x), &pow($x,$y), + + &sqrt($x)

Exponential, power and square + + root, i.e.,ex, xy and /x. $x and $y can be pure + + numbers

 

abs(x), sgn(x)

&abs($x), &sgn($x)

Abs takes the absolute value + + of x while sgn(x) returns 1, 0 or -1 depending on the value of x. For + + x>0, sgn(x) = 1, for x=0, sgn(x) = 0 and for x<0, sgn(x) = -1. + + $x can be a pure number

 

erf(x), erfc(x)

&erf($x), &erfc($x)

Error function.  erf = + + 2/sqrt(pi) integral (0,x) et-sq and erfx(x) + + = 1.0 - erf(x).  $x can be a pure number

 

ceil(x), floor(x)

&ceil($x), &floor($x)

Ceil function returns an integer + + rounded up whereas floor function returns and integer rounded down. + + If x is an integer than it returns the value of the integer. $x can + + be a pure number

 

min(...), max(...)

&min(...), &max(...)

Returns the minimum/ maximum + + value of a list of arguments if the arguments are numbers. If the arguments + + are strings then it returns a string sorted according to the ASCII codes

 

factorial(n)

&factorial($n)

Argument (n) must be an integer + + else it will round down. The largest value for n is 170. $n can be a + + pure number

 

N%M

$N%$M

N and M are integers and returns + + the remainder (in integer) of N/M. $N and $M can be pure numbers

 

sinh(x), cosh(x), tanh(x)

&sinh($x), &cosh($x), + + &tanh($x)

Hyperbolic functions. $x can + + be a pure number

 

asinh(x), acosh(x), atanh(x)

&asinh($x), &acosh($x), + + &atanh($x)

Inverse hyperbolic functions. + + $x can be a pure number

 

/DIS($x,"nn")

&format($x,"nn")

Display or format $x as nn where + + nn is nF or nE and n is an integer.

 The difference is obvious.

Not in CAPA

&prettyprint($x,"nn")

Display or format $x as nn where + + nn is nF or nE and n is an integer. In E mode it will attempt to generate + + a pretty x10^3 rather than a E3 following the number

 

roundto(x,n)

&roundto($x,$n)

Rounds a real number to n decimal + + points. $x and $n can be pure numbers

 

web("a","b","c") + + or web(a,b,c)

&web("a","b","c") + + or &web($a,$b,$c)

Returns either a, b or c depending + + on the output medium. a is for plain ASCII, b for tex output and c for + + html output

 

html("a") or html(a)

&html("a") or + + &html($a)

Output only if the output mode + + chosen is in html format

 

jn(m,x)

&j0($x), &j1($x), &jn($m,$x), + + &jv($y,$x)

Bessel functions of the first + + kind with orders 0, 1 and m respectively. For jn(m,x), m must be an + + integer whereas for jv(y,x), y is real. $x can be a pure number. $m + + must be an integer and can be a pure integer number. $y can be a pure + + real number

In CAPA, j0, j1 and jn are contained + + in one function, jn(m,x) where m takes the value of 0, 1 or 2. jv(y,x) + + is new to LON-CAPA.

yn(m,x)

&y0($x), &y1($x), &yn($m,$x), + + &yv($y,$x)

Bessel functions of the second + + kind with orders 0, 1 and m respectively. For yn(m,x), m must be an + + integer whereas for yv(y,x), y is real. $x can be a pure number. $m + + must be an integer and can be a pure integer number. $y can be a pure + + real number

In CAPA, y0, y1 and yn are contained + + in one function, yn(m,x) where m takes the value of 0, 1 or 2. yv(y,x) + + is new to LON-CAPA.

random(l,u,d)

&random($l,$u,$d)

Returns a uniformly distributed + + random number between the lower bound, l and upper bound, u in steps + + of d. $l, $u and $d can be pure numbers

In CAPA, all the 3 arguments + + must be of the same type. However, now you can mix the type

choose(i,...)

&choose($i,...)

Choose the ith item from the + + argument list. i must be an integer greater than 0 and the value of + + i should not exceed the number of items. $i can be a pure integer

 

/MAP(seed;w,x,y,z;a,b,c,d)

Option 1 - &map($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) + + or
+ + Option 2 - &map($seed,\@mappedArray,[$a,$b,$c,$d])
+ + Option 3 - @mappedArray = &map($seed,[$a,$b,$c,$d])
+ + Option 4 - ($w,$x,$y,$z) = &map($seed,\@a)
+ + where $a='A'
+ + $b='B'
+ + $c='B'
+ + $d='B'
+ + $w, $x, $y, and $z are variables

Assigns to the variables $w, + + $x, $y and $z the values of the $a, $b, $c and $c (A, B, C and D). The + + precise value for $w .. depends on the seed. (Option 1 of calling map). + + In option 2, the values of $a, $b .. are mapped into the array, @mappedArray. + + The two options illustrate the different grouping. Options 3 and 4 give + + a consistent way (with other functions) of mapping the items. For each + + option, the group can be passed as an array, for example, [$a,$b,$c,$d] + + => \@a.

In CAPA, the arguments are divided + + into three groups separated by a semicolon ;. In LON-CAPA, the separation + + is done by using [] brackets or using an array @a. Note the backslash + + (\) before the arguments in the second and third groups.

rmap(seed;a,b,c,d;w,x,y,z)

Option 1 - &rmap($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) + + or
+ + Option 2 - &rmap($seed,\@rmappedArray,[$a,$b,$c,$d])
+ + Option 3 - @rmapped_array = &rmap($seed,[$a,$b,$c,$d])
+ + Option 4 - ($w,$x,$y,$z) = &rmap($seed,\@a)
+ + where $a='A'
+ + $b='B'
+ + $c='B'
+ + $d='B'
+ + $w, $x, $y, and $z are variables

The rmap functions does the + + reverse action of map if the same seed is used in calling map and rmap. + +

In CAPA, the arguments are divided + + into three groups separated by a semicolon ;. In LON-CAPA, the separation + + is done by using [] brackets (with create an unamed vector reference) + + or using an array @a. Note the backslash (\) before the arguments in + + the second and third groups (Which cause Perl to send to variable locations + + rather than the variable values, similar to a C pointer).

NOT IMPLEMENTED IN CAPA

$a=&xmlparse($string)

Runs the internal parser over + + the argument parsing for display. Warning + + This will result in different strings in different targets. Don't use + + the results of this function as an answer.

New to LON-CAPA

tex(a,b), tex("a","b")

&tex($a,$b), &tex("a","b")

Returns a if the output mode + + is in tex otherwise returns b

 

var_in_tex(a)

&var_in_tex($a)

Equivalent to tex("a","")

 

to_string(x), to_string(x,y)

&to_string($x), &to_string($x,$y)

If x is an integer, returns + + a string. If x is real than the output is a string with format given + + by y. For example, if x = 12.3456, &to_string(x,".3F") + + = 12.345 and &to_string(x,".3E") = 1.234E+01.

 

capa_id(), class(), section(), + + set(), problem()

&class(), &section()

Returns null string, class descriptive + + name, section number, set number and null string.

capa_id(), set() and problem() + + are no longer used. Currently, they return a null value.

name(), student_number()

&name(), &student_number()

Return the full name in the + + following format: lastname, firstname initial. Student_number returns + + the student 9-alphanumeric string. If undefined, the functions return + + null.

 

open_date(), due_date(), answer_date()

&open_date(), &due_date(), + + &answer_date()

Problem open date, due date + + and answer date. The time is also included in 24-hr format.

Output format for time is changed + + slightly. If pass noon, it displays ..pm else it displays ..am. So 23:59 + + is displayed as 11:59 pm.

get_seed(), set_seed()

Not implemented

Get and set the random seed.

 

sub_string(a,b,c)

&sub_string($a,$b,$c)
+ + perl  substr function. However, note the differences

Retrieve a portion of string + + a starting from b and length c. For example,  $a = "Welcome + + to LON-CAPA"; $result=&sub_string($a,4,4); then $result is + + "come"

Perl intrinsic function, substr(string,b,c) + + starts counting from 0 (as opposed to 1). In the example to the left, + + substr($a,4,4) returns "ome ".

array[xx]

@arrayname
+ + Array is intrinsic in perl. To access a specific element use $arrayname[$n] + + where $n is the $n+1 element since the array count starts from 0

"xx" can be a variable + + or a calculation.

In LON-CAPA, an array is defined + + by @arrayname. It is not necessary to specify the dimension of the array. 

array_moments(B,A)

@B=&array_moments(@A)

Evaluates the moments of an + + array A and place the result in array B[i] where i = 0 to 4. The contents + + of B are as follows: B[0] = number of elements, B[1] = mean, B[2] = + + variance, B[3] = skewness and B[4] = kurtosis.

In CAPA, the moments are passed + + as an array in the first argument whereas in LON-CAPA, the array containing + + the moments are set equal to the function.

array_max(Name), array_min(Name)

&min(@Name), &max(@Name)

In LON-CAPA to find the maximum + + value of an array, use &max(@arrayname)  and to find the minimum + + value of an array, use &min(@arrayname)

Combined with the min and max + + functions defined earlier.

init_array(Name)

undef @name

To destroy the contents of an + + array, use

Use perl intrinsic undef function.

random_normal (return_array,item_cnt,seed,av,std_dev)

@return_array=&random_normal + + ($item_cnt,$seed,$av,$std_dev)

Generate $item_cnt deviates + + of normal distribution of average $av and standard deviation $std_dev. + + The distribution is generated from seed $seed

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_beta (return_array,item_cnt,seed,aa,bb)

@return_array=&random_beta + + ($item_cnt,$seed,$aa,$bb)
+ + NOTE: Both $aa and $bb MUST be greater than 1.0E-37.

Generate $item_cnt deviates + + of beta distribution. The density of beta is: X^($aa-1) *(1-X)^($bb-1) + + /B($aa,$bb) for 0<X<1.

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_gamma (return_array,item_cnt,seed,a,r)

@return_array=&random_gamma + + ($item_cnt,$seed,$a,$r)
+ + NOTE: Both $a and $r MUST be positive.

Generate $item_cnt deviates + + of gamma distribution. The density of gamma is: ($a**$r)/gamma($r) * + + X**($r-1) * exp(-$a*X).

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_exponential (return_array,item_cnt,seed,av)

@return_array=&random_exponential + + ($item_cnt,$seed,$av)
+ + NOTE: $av MUST be non-negative.

Generate $item_cnt deviates + + of exponential distribution.

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_poisson (return_array,item_cnt,seed,mu)

@return_array=&random_poisson + + ($item_cnt,$seed,$mu)
+ + NOTE: $mu MUST be non-negative.

Generate $item_cnt deviates + + of poisson distribution.

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_chi (return_array,item_cnt,seed,df)

@return_array=&random_chi + + ($item_cnt,$seed,$df)
+ + NOTE: $df MUST be positive.

Generate $item_cnt deviates + + of chi_square distribution with $df degrees of freedom.

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

random_noncentral_chi (return_array,item_cnt,seed,df,nonc)

@return_array=&random_noncentral_chi + + ($item_cnt,$seed,$df,$nonc)
+ + NOTE: $df MUST be at least 1 and $nonc MUST be non-negative.

Generate $item_cnt deviates + + of noncentral_chi_square distribution with $df degrees of freedom and + + noncentrality parameter $nonc.

In CAPA the results are passed + + as the first argument whereas in LON-CAPA the results are set equal + + to the function.

NOT IMPLEMENTED IN CAPA

@return_array=&random_f + + ($item_cnt,$seed,$dfn,$dfd)
+ + NOTE: Both $dfn and $dfd MUST be positive.

Generate $item_cnt deviates + + of F (variance ratio) distribution with degrees of freedom $dfn (numerator) + + and $dfd (denominator).

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_noncentral_f + + ($item_cnt,$seed,$dfn,$dfd,$nonc)
+ + NOTE: $dfn must be at least 1, $dfd MUST be positive, and $nonc must + + be non-negative.

Generate $item_cnt deviates + + of noncentral F (variance ratio) distribution with degrees of freedom + + $dfn (numerator) and $dfd (denominator). $nonc is the noncentrality + + parameter.

New to LON-CAPA

NOT DOCUMENTED IN CAPA

@return_array=&random_multivariate_normal + + ($item_cnt,$seed,\@mean,\@covar)
+ + NOTE: @mean should be of length p array of real numbers. @covar should + + be a length p array of references to length p arrays of real numbers + + (i.e. a p by p matrix.

Generate $item_cnt deviates + + of multivariate_normal distribution with mean vector @mean and variance-covariance + + matrix.

Note the backslash before the + + @mean and @covar arrays.

NOT IMPLEMENTED IN CAPA

@return_array=&random_multinomial + + ($item_cnt,$seed,@p)
+ + NOTE: $item_cnt is rounded with int() and the result must be non-negative. + + The number of elements in @p must be at least 2.

Returns single observation from + + multinomial distribution with $item_cnt events classified into as many + + categories as the length of @p. The probability of an event being classified + + into category i is given by ith element of @p. The observation is an + + array with length equal to @p, so when called in a scalar context it + + returns the length of @p. The sum of the elements of the obervation + + is equal to $item_cnt.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_permutation + + ($item_cnt,@array)

Returns @array randomly permuted.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_uniform + + ($item_cnt,$seed,$low,$high)
+ + NOTE: $low must be less than or equal to $high.

Generate $item_cnt deviates + + from a uniform distribution.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_uniform_integer + + ($item_cnt,$seed,$low,$high)
+ + NOTE: $low and $high are both passed through int(). $low must be less + + than or equal to $high.

Generate $item_cnt deviates + + from a uniform distribution in integers.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_binomial + + ($item_cnt,$seed,$nt,$p)
+ + NOTE: $nt is rounded using int() and the result must be non-negative. + + $p must be between 0 and 1 inclusive.

Generate $item_cnt deviates + + from the binomial distribution with $nt trials and the probabilty of + + an event in each trial is $p.

New to LON-CAPA

NOT IMPLEMENTED IN CAPA

@return_array=&random_negative_binomial + + ($item_cnt,$seed,$ne,$p)
+ + NOTE: $ne is rounded using int() and the result must be positive. $p + + must be between 0 and 1 exclusive.

Generate an array of $item_cnt + + outcomes generated from negative binomial distribution with $ne events + + and the probabilty of an event in each trial is $p.

New to LON-CAPA

+ +

<script> Variables

+ + + +

Form internals

+ +

Form elements used for homework editing/response

+ +

the form is named lonhomework

+ +

Viewing a problem (either CSTR or RES space)

+ + + +

Editing a problem (Edit mode)

+ +

tagdepth referes to the current value of the xmlparsers tagdepth couter ($Apache::lonxml::currentdepth)

+ +

Note: the file edit.pm has many helper functions for creating the standard + + elements for editing a tag and it's attributes, all of those functions follow + + these conventions

+ + + + + +

Symbs

+ +

To identify a specific instance of a resource, LON-CAPA uses symbols or Ňsymbs.Ó + + These identifiers are built from the URL of the map, the resource number of + + the resource in the map, and the URL of the resource itself. The latter is + + somewhat redundant, but might help if maps change.

+ +

An example is

+ +

 msu/korte/parts/part1.sequence___19___msu/korte/tests/part12.problem

+ +

The respective map entry is

+ +

 <resource + + id="19" src="/res/msu/korte/tests/part12.problem"     + +

+ +

  title="Problem + + 2">

+ +

 </resource>

+ +

Symbs are used by the random number generator, as well as + + to store and restore data specific to a certain instance of for example a + + problem.

+ +

Store / Restore

+ +

2 important functions in lonnet.pm are &Apache::lonnet::cstore() and &Apache::lonnet:restore() (and + + &Apache::lonnet::store(), which is is the non-critical message twin of cstore). These functions are for handlers to store a perl hash to + + a userŐs permanent data space in an easy manner, and to retrieve it again + + on another call. It is expected that a handler would use this once at the + + beginning to retrieve data, and then again once at the end to send only the + + new data back.

+ +

The data is stored in the userŐs data directory + + on the userŐs homeserver under the ID of the course.

+ +

The hash that is returned by restore will have all of the previous value for all of the elements + + of the hash.

+ +

Example:

+ +

#creating a hash

+ +

my %hash;

+ +

$hash{'foo'}='bar';

+ +

#storing it

+ +

&Apache::lonnet::cstore(\%hash);

+ +

#changing a value

+ +

$hash{'foo'}='notbar';

+ +

#adding a new value

+ +

$hash{'bar'}='foo';

+ +

&Apache::lonnet::cstore(\%hash);

+ +

#retrieving the hash

+ +

my %history=&Apache::lonnet::restore();

+ +

#print the hash

+ +

foreach my $key (sort(keys(%history))) + + {

+ +

    print("\%history{$key} + + = $history{$key}");

+ +

}

+ +

Will print out:

+ +

%history{1:foo} = bar

+ +

%history{1:keys} = foo:timestamp

+ +

%history{1:timestamp} + + = 990455579

+ +

%history{2:bar} = foo

+ +

%history{2:foo} = notbar

+ +

%history{2:keys} = foo:bar:timestamp

+ +

%history{2:timestamp} + + = 990455580

+ +

%history{bar} = foo

+ +

%history{foo} = notbar

+ +

%history{timestamp} = + + 990455580

+ +

%history{version} = 2

+ +

Note that the special hash entries keys, + + version and timestamp were + + added to the hash. version will be + + equal to the total number of versions of the data that have been stored. The + + timestamp attribute will be the UNIX time the hash was stored. keys is available in every historical section to list which keys + + were added or changed at a specific historical revision of a hash.

+ +

Warning do not store the hash that restore returns directly. This + + will cause a mess since it will restore the historical keys as if the were + + new keys. I.E. 1:foo will become 1:1:foo etc.

+ +

Calling convention:

+ +

  my %record=&Apache::lonnet::restore($symb,$courseid,$domain,$uname,$home);

+ +

  &Apache::lonnet::cstore(\%newrecord,$symb,$courseid,$domain,$uname,$home);

+ +

Arguments (only %newrecord is required the rest + + are somewhat optional, read the details):

+ +

á      + + $symb - a string containing the internal name of the specific instance + + of a resource. Usually this value can be gotten from &Apache::lonnet::symbread($filename). If the argument is blank, it will attempt to use symbread() for it. If the result is ambiguous store/restore will fail. + +

+ +

á      + + $courseid - the internal name for a course, usually found in $ENV{'request.course.id'} which is what will be looked at if no value is passed to + + the functions.

+ +

á      + + $domain - the domain that the user belongs to, usually found in $ENV{'user.domain'} which is what will be looked at if no value is passed to + + the functions.

+ +

á      + + $uname - the login name for the user, usually found in $ENV{'user.name'} which is what will be looked at if no value is passed to + + the functions.

+ +

á      + + $home - the homeserver for the user, usually found in $ENV{'user.home'} but can be easily gotten from a domain and name through &Apache::lonnet::homeserver($uname,$domain). If no value is passed to store/restore the value in %ENV + + will be used.

+ +

á      + + %newrecord - the hash to store being passed by reference

+ +

Return values:

+ +

á      + + an empty string - the function was unable to determine exactly where to store + + or restore from. At least one of the "optional" arguments was unable + + to be determined.

+ +

á      + + a hash - restore successfully read a old hash for this specific + + user / resource instance.

+ +

á      + + no_such_host - the $home specfied + + desn't exist in the network.

+ +

á      + + con_delayed - the $home was uncontactable + + at this time. The store will be delayed until it is again available.

+ +

á      + + con_failed - the $home was uncontactable + + at this time and store was unable to delay the store until a later time. The + + store failed.

+ +

á      + + ok - the store completed succesfully

+ +

á      + + error: - remote server failied to store or restore the reason follows + + the :

+ +

Mandatory Homework Data

+ + 
 
+ + 
<Provided by &EXT() and set external to the resource, required>
+ + 
resource.partid.opendate   #unix time of when the local machine should let the
+ + 
                           #student in
+ + 
 
+ + 
resource.partid.duedate    #unix time of when the local machine should stop
+ + 
                           #accepting answers
+ + 
 
+ + 
resource.partid.answerdate #unix time of when the local machine should
+ + 
                           #provide the correct answer to the student
+ + 
 
+ + 
resource.partid.weight     # points the problem is worth
+ + 
 
+ + 
resource.partid.maxtries   # maximum number of attempts the student can have
+ + 
 
+ + 
resource.partid.type       # type of problem homework can be:
+ + 
                           # homework - randomized, graded, stored with
+ + 
                           #            requesting user, full feeback
+ + 
                           # exam - randomized, graded, stored with
+ + 
                           #        requesting user, minimal feedback
+ + 
                           # form - unrandomized, ungraded, stored with
+ + 
                           #        specified user, full feedback
+ + 
                           # survey - unrandomized, ungraded, stored with
+ + 
                           #          requesting user, full feedback
+ + 
 
+ + 
 
+ + 
 
+ + 
<numerical/formula/response needed: (has a default if nonexistant)>
+ + 
 
+ + 
resource.partid.responseid.tol   # lots of possibilities here
+ + 
                    # percentage, range (inclusive and exclusive),
+ + 
                     # variable name, etc
+ + 
                    # 3%
+ + 
                    # 0.5
+ + 
                    # .05+
+ + 
                    # 3%+
+ + 
                    # 0.5+,.005
+ + 
 
+ + 
resource.partid.responseid.sig  # one or two comma sepearted integers,   
+ + 
                                # specifying the number of significatn figures
+ + 
                                # a student must use
+ + 
 
+ + 
 
+ + 
 
+ + 
<Problem sets using cstore (required):>
+ + 
resource.partid.solved # if not set, problem yet to be viewed
+ + 
                # incorrect_attempted == incorrect and attempted
+ + 
                # correct_by_student == correct by student work
+ + 
                # correct_by_override == correct, instructor override
+ + 
                # incorrect_by_override == incorrect, instructor override
+ + 
                # excused == excused, problem no longer counts for student
+ + 
                # '' (empty) == not attempted
+ + 
                # ungraded_attempted == an ungraded answer has been
+ + 
                                          sumbitted and stored
+ + 
resource.partid.tries  # positive integer of number of unsuccessful attempts
+ + 
                # made, malformed answers don't count if feedback is
+ + 
                # on
+ + 
 
+ + 
resource.partid.awarded # float between 0 and 1, percentage of
+ + 
                 # resource.weight that the stundent earned.
+ + 
 
+ + 
resource.partid.award # final detailed award that was applied to the entire
+ + 
                      # part of the question, check awarddetail below for
+ + 
                      # possibilities
+ + 
 
+ + 
resource.partid.previous # boolean, is this submission a previous submission
+ + 
 
+ + 
resource.partid.responseid.submissons
+ + 
                    # the student submitted string for the part.response
+ + 
 
+ + 
resource.partid.responseid.awarddetail
+ + 
                     # list of all of the results of grading the submissions
+ + 
                     # in detailed form of the specific failure
+ + 
                      #Possible values:
+ + 
                     # EXACT_ANS, APPROX_ANS : student is correct
+ + 
                     # NO_RESPONSE : student submitted no response
+ + 
                     # MISSING_ANSWER : student submitted some but not
+ + 
                     #                   all parts of a response
+ + 
                     # WANTED_NUMERIC : expected a numeric answer and
+ + 
                     #                   didn't get one
+ + 
                      # SIG_FAIL : incorrect number of Significant Figures
+ + 
                     # UNIT_FAIL : incorrect unit
+ + 
                     # UNIT_NOTNEEDED : Submitted a unit when one shouldn't
+ + 
                     # NO_UNIT : needed a unit but none was submitted
+ + 
                      # BAD_FORMULA : syntax error in submitted formula
+ + 
                     # INCORRECT : answer was wrong
+ + 
                     # SUBMITTED : submission wasn't graded
+ + 
                     # ERROR : unable to get a grade
+ + 
 
+ + 
resource.partid.responseid.message (optional) (not yet supported)
+ + 
                       # a message that should be shown to the student
+ + 
 
+ + 
resource.partid.bonustries (optional) (not yet supported)
+ + 
                     # if set, added to the maxtries parameter for student
+ + 
                     # total number of tries overall
+ + 
 
+ +

Sample Problems

+ +

A Simple Problem

+ +

<problem>

+ +

        + + <script type="loncapa/perl">

+ +

$length=&random(10,99,.1);

+ +

$width=&random(1,10,.01);

+ +

@area=($length*($width*10));

+ +

        + + </script>

+ +

What + + is the area of a box $length mm in length and

+ +

&format($width,"2E") + + cm in width.

+ +

        + + <numericalresponse id="11" answer="@area" units="mm^2">

+ +

                + + <textline></textline>

+ +

                + + <responseparam name="tol" type="tolerance" default="5%"></responseparam>

+ +

        + + </numericalresponse>

+ +

</problem>

+ +

A More Complex Problem

+ +

<problem>

+ +

<displayduedate + + />

+ +

<p><displaytitle + + /></p>

+ +

<script type="loncapa/perl">

+ +

$vF="<b> + + F<sub>1</sub> </b>";

+ +

$vF1="<b> + + F<sub>1</sub> </b>";

+ +

$vF2="<b> + + F<sub>2</sub> </b>";

+ +

$mF="|<b>F</b>|";

+ +

$F1mag="|<b>F<sub>1</sub></b>|";

+ +

$F2mag="|<b>F<sub>2</sub></b>|";

+ +

$trq1mag="|<b> + + <font face=symbol>t</font><sub>1</sub></b>|";

+ +

$trq2mag="|<b> + + <font face=symbol>t</font><sub>2</sub></b>|";

+ +

$Q1="Q<sub>1</sub>";

+ +

$Q2="Q<sub>2</sub>";

+ +

$tau="<font + + face=symbol>t</font>";

+ +

$tau1="<font + + face=symbol><b>t</b></font><sub>1</sub>";

+ +

   $val=&random(1,4,1);

+ +

   $tp=&choose($val,"her","her","his","his");

+ +

   $sd=&choose($val,"daughter","niece","nephew","son");

+ +

</script>

+ +

<startouttext + + />

+ +

$trq1mag and $trq2mag + + are the magnitudes of the torques produced repectively by

+ +

forces $vF1 and $vF2 + + with respect the pivot P. The magnitudes of $vF1 is

+ +

$F1mag and that of + + $vF2 is $F2mag. $Q1 and $Q2 are the locations

+ +

on a rigid body where + + $vF1 and $vF2 act. 

+ +

<endouttext />

+ +

<optionresponse + + max="600">

+ +

        + + <foilgroup options="('Correct','Incorrect','Can not tell')">

+ +

                + + <conceptgroup concept="Effect of the moment-arm on the torque">

+ +

                        + + <foil name="1a" value="Incorrect">

+ +

                          + + For $F1mag larger than $F2mag , $trq1mag is larger than $trq2mag

+ +

                        + + </foil>

+ +

                        + + <foil name="1b" value="Incorrect">

+ +

                          + + For $F1mag smaller than $F2mag , $trq1mag is smaller than $trq2mag

+ +

                        + + </foil>

+ +

           + +              <foil + + name="1c" value="Correct">

+ +

                          + + For $F1mag larger than $F2mag , $trq1mag can be less  than $trq2mag

+ +

                        + + </foil>

+ +

                        + + <foil name="1d" value="Correct">

+ +

                          + + For $F1mag smaller than $F2mag , $trq1mag can be larger  than $trq2mag

+ +

                        + + </foil>

+ +

                + + </conceptgroup>

+ +

                + + <conceptgroup concept="For a given pivot, relation of force vector + + to torque.">

+ +

                        + + <foil name="2a" value="Correct">

+ +

                  + + The moment-arm of $vF is the shortest distance from P to the line along $vF + + .

+ +

                        + + </foil>

+ +

                        + + <foil name="2b" value="Incorrect">

+ +

                          + + The moment-arm of $vF is the shortest distance from P to $vF vector.

+ +

                        + + </foil>

+ +

                        + + <foil name="2c" value="Correct">

+ +

                          + + The moment-arm of $vF is not the distance from P to Q<sub>1</sub>.

+ +

                + +         </foil>

+ +

                        + + <foil name="2d" value="Incorrect">

+ +

                          + + The moment-arm of $vF is the distance from P to Q<sub>1</sub>.

+ +

                        + + </foil>

+ +

                + + </conceptgroup>

+ +

                + + <conceptgroup concept="Torque is force x moment-arm.">

+ +

                        + + <foil name="3a" value="Correct">

+ +

                          + + $trq1mag equals to the product of the moment-arm and $F1mag .

+ +

                      + + </foil>

+ +

                        + + <foil name="3b" value="Incorrect">

+ +

                        + + $trq1mag equals to $F1mag times the distance from Q<sub>1</sub> + + to P.

+ +

                        + + </foil>

+ +

                        + + <foil name="3c" value="Correct">

+ +

                          + + $trq1mag is not equal to the product of $F1mag and the distance from Q<sub>1</sub> + + to P.

+ +

                        + + </foil>

+ +

                        + + <foil name="3d" value="Incorrect">

+ +

                        + + $trq1mag is not equal to the product of the moment-arm and $F1mag .

+ +

         + +                </foil>

+ +

                + + </conceptgroup>

+ +

                + + <conceptgroup concept="Pivot point is required to calculate torque">

+ +

                        + + <foil name="4a" value="Correct">

+ +

                         + + $tau1 vector depends on the location of P.

+ +

                        + + </foil>

+ +

                        + + <foil name="4b" value="Incorrect">

+ +

                         + + $tau1 vector does not depend on the location of P.

+ +

                        + + </foil>

+ +

                        + + <foil name="4c" value="Correct">

+ +

                         + + $tau1 vector has no meaning unless a pivot is selected.

+ +

                        + + </foil>

+ +

                        + + <foil name="4d" value="Incorrect">

+ +

                         + + $tau1 vector can be determined without selecting P.

+ +

                        + + </foil>

+ +

                + + </conceptgroup>

+ +

                + + <conceptgroup concept="torque from 2 forces acting along same line">

+ +

                        + + <foil name="5a" value="Correct">

+ +

                          + + Two equal forces, acting on a body along the same line but at different positions, + + produce equal torques with respect to a given pivot."

+ +

                        + + </foil>

+ +

                        + + <foil name="5b" value="Incorrect">

+ +

                          + + Two equal forces, along the same line, produce equal torques with respect + + to a given pivot only if they act at the same point on a body."

+ +

                        + + </foil>

+ +

                        + + <foil name="5c" value="Incorrect">

+ +

                          + + Two equal forces acting on a body along the same line but at different positions, + + produce equal torques for only one pivot."

+ +

                        + + </foil>

+ +

                + + </conceptgroup>

+ +

                + + <foil name="6" value="unused">

+ +

                        + + This foil will never display since it is unused.

+ +

                + + </foil>

+ +

        + + </foilgroup>

+ +

        + + <notsolved>

+ +

                + + <hintgroup>

+ +

Think the definition + + of the torque. The force and the moment-arm respect to the pivot. 

+ +

                + + </hintgroup>

+ +

      + +   </notsolved>

+ +

</optionresponse>

+ +

</problem>

+ +

 

+ +

+ +

Fig. 3.1.1 Đ Internal Structure of Homework Handler

+ +
+ +
+ +
+ + + + +