doc/homework/homework5.html - view

File: [LON-CAPA] / doc / homework / homework5.html
Revision 1.8: download - view: text, annotated - select for diffs
Fri Jul 13 16:15:01 2001 UTC (23 years, 4 months ago) by albertel
Branches: MAIN
CVS tags: HEAD

-implemented <stringresponse>
-fixed editor to remove trailing and leading spaces from user supplied values.
-updated documentation

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>LON-CAPA Homework System</title> </head> <body bgcolor="white"> <h1>LON-CAPA Homework System</h1> <h2>Tags</h2> <ul> <li> Response tags Arguments for all response tags <ul> <li> ID, if this isn't set it will be set during the publication step. It is used to assign parameters names in a way that can be tracked if an instructor modifies things by hand. </li> <li> name optional, if set, it will be used by the resource assembly tool when one is modifying parameters. </li> </ul> Implemented response tags <ul> <li> <responseparam> if it appears it should be inside of a <*response> tag, defines an externally adjustable parameter for this question. Arguments: <ul> <li> default required, specifies a default value for the parameter </li> <li> name required, specifies an internal name for the parameter </li> <li> type required specifies the type of parameter, one of "tolerance", "int", "float", "string", "date" (configuration of paramters is handled by lonparmset.pm and parameter.html) </li> <li> description a string describing the parameter, this is what is used to talk about a parameter outside of a problem </li> </ul> </li> <li> <numericalresponse> implements a numerical answer, it needs an internal <textline> for the response to go in. It checks all styles of numerical supported in CAPA. Possible args are: <ul> <li>answer required, specifies the correct answer, may be either a perl list or scalar</li> <li>units optional, specifies unit of correct answer, CAPA style</li> </ul> </li> <li> <stringresponse> implements a string answer, it needs an internal <textline> for the response to go in. It can check the string for either case or order. <ul> <li>answer required, specifies the correct answer, may be either a perl list or scalar</li> <li>type optional, CAPA style str args, cs/ci/mc <ul> <li>cs - case senesitive, order important</li> <li>ci - case insenesitive, order important</li> <li>mc - case insenesitive, order unimportant</li> </ul> </li> </ul> <li> <essayresponse> implements a ungraded large text response, it need an internal <textarea> for the response to go in. </li> <li> <imageresponse> implements a image click style image submission, uses the foil structure tags <a href="#foil">below</a>. Additional tags that should appear in a <foil> are: <ul> <li><image> required, the contained text specifies a published graphical resource that is the image used, should only appear once per foil</li> <li><rectangle> required, the contained text specifies a rectangular area that is correct, should look like (1,2)-(3,4), at least 1 required</li> <li><text> required, the contained text is printed on top of the image.</li> </ul> </li> <li> <optionresponse> implements a "select from these choices" style question, the choices are specified by the instructor, it uses the foil structure tags <a href="#foil">below</a> with this additional args: <ul> <li> <foilgroup> is required to have options which should be a perl list of possible options for the student. </li> </ul> </li> <li> <radiobuttonresponse> implements a true / false style question with 1 correct answer.it uses the foil structure tags <a href="#foil">below</a> but the value of a <foil>can only be "true" or "false" or "unused" </li> </ul> <li> <a name="foil">Foil Structure Tags</a> All tags that implement a foil structure have an optional arg of max that controls the maximum number of total foils to show. <ul> <li> <foilgroup> required, must be the tag that surrounds all foil definitions </li> <li> <foil> required, all data inside is a possible foil </li> <li> <conceptgroup> optional, surrounds a collection of <foil>, when a problem is displayed only one of the contained <foil>is selected for display. It receives one required argument concept. </li> </ul> </li> <li> Hint structure All of these tags must appear inside a <*response> tag. <ul> <li> <hintgroup> Tag that surrounds all of a hint. </li> <li> <hintpart> required, Tag to implement conditional hints. It has a required argument on. When a <*hint> tag named the same as the value the on attribute evaluates to be correct the <hintpart> will show. If no other <hintpart> are to show then all hintparts with a on of "default" will show </li> <li> <numericalhint> has all the arguments that <numericalresponse>, does and the required attribute name which should be set to the value of which <hintpart> will be shown. </li> </ul> </li> <li> Input Tags This group of tags implement a mechanism for getting data for students, they will usually be used by a <*response>. <ul> <li> <textarea> creates a Large text input box, If data appears between the start and end tags, the data will appear i the textarea if the student has not yet made a submission. Additionally it takes two arguments rows and cols which control the height and width of the area respectively. It defaults to 10 and 80. </li> <li> <textline> creates a single line of input element, it accepts 1 argument size which controls the width on the textline, it defaults to 20. </li> </ul> </li> <li> Output Tags This group of tags generate useful pieces of output. <ul> <li> <displayduedate> this will insert the current duedate if one is set into the document. It is generated to be inside a table of 1x1 elements </li> <li> <displaytitle> this will insert the title of the problem from the metadata of the problem </li> <li> <window> the text in between is put in a popup javascript window </li> </ul> </li> <li> Scripting These tags allow the document to behave programatically <ul> <li> <display> the intervening perl script is evaluated in the safe space and the return value of the script replaces the entire tag </li> <li> <import> causes the parse to read in the file named in the body of the tag and parse it as if the entire text of the file had existed at location of the tag </li> <li> <parserlib> the enclosed filename contains definitions for new tags </li> <li> <script> if the argument type is set to "loncapa/perl" the enclosed data is a perl script which is evaluated inside the perl Safe space. The return value of the script is ignored. </li> <li> <scriptlib> the enclosed filename contains perl code to run in the safe space </li> <li> <block> has a required argument condition that is evaluated, it the condition is true everything inside the tag is evaluated, if it is false everything inside the block tag is skipped </li> <li> <notsolved> everything inside the tag is skipped if the problem is "solved" </li> <li> <postanswerdate> everything inside the tag is skipped if the problem is before the answer date </li> <li> <preduedate> everything inside the tag is skipped if the problem is after the due date </li> <li> <randomlist> the enclosed tags are parsed in a stable random order </li> <li> <solved> everything inside the tag is skipped if the problem is "not solved" </li> <li> <while> implements a while loop, required argument condition is a perl scriptlet that when evaluated results in a true or false value, on true the entirety of the text between the whiles is parsed. The condition is tested again, etc. If false it goes to the next node in the parse. </li> </ul> </li> <li> Structure Tags These tags give the problem a structure and take care of the recording of data and giving the student messages. <ul> <li> <problem> must be the first tag in the file, this tag sets up the header of the webpage and generates the submit buttons, it also handles due dates properly </li> <li> <part> must be below <problem> if it is going to be used. It does many of the same tasks as <problem> but allows multiple separate problems to exist in a single file. </li> <li> <startouttext><endouttext> these tags are somewhat special, they must have no internal text and occur in pairs. Their use is to mark up the problem so the web editor knows what sections should be edited in a plain text block on the web. </li> </ul> </li> </ul> <h2><script> Functions</h2> A list of functions that have been written that are available in the Safe space scripting environment inside a problem. <ul> <li>sin(x), cos(x), tan(x)</li> <li>asin(x), acos(x), atan(x), atan2(y,x)</li> <li>log(x), log10(x)</li> <li>exp(), pow(x,y), sqrt(x)</li> <li>abs(x), sgn(x)</li> <li>erf(x), erfc(x)</li> <li>ceil(x), floor(x)</li> <li>min(...), max(...)</li> <li>factorial(n)</li> <li>N%M</li> <li>sinh(x), cosh(x), tanh(x)</li> <li>asinh(x), acosh(x), atanh(x)</li> <li>roundto(x,n)</li> <li>web("a","b","c") or web(a,b,c)</li> <li>html("a") or html(a)</li> <li>j0(x), j1(x), jn(n,x), jv(y,x)</li> <li>y0(x), y1(x), yn(n,x), yv(y,x)</li> <li>random</li> <li>choose</li> <li>tex("a","b") or tex(a,b)</li> <li>var_in_tex(a)</li> <li>to_string(x), to_string(x,y)</li> <li>class(), section()</li> <li>name(), student_number()</li> <li>open_date(), due_date(), answer_date()</li> <li>sub_string()</li> <li>array_moments(array)</li> <li>format(x,y)</li> <li>map(...)</li> <li>caparesponse_check</li> <li>caparesponse_check_list</li> </ul>  Detailed descriptions of each function and comparison with CAPA. <table border=1> <tr> <td valign="top">CAPA Functions</b</td> <td valign="top">LON-CAPA</b</td> <td valign="top">Descriptions</b</td> <td valign="top">Differences (if any)</b</td> </tr> <tr> <td valign="top">sin(x), cos(x), tan(x)</td> <td valign="top">&sin($x), &cos($x), &tan($x)</td> <td valign="top">Trigonometric functions where x is in radians. $x can be a pure number, i.e., you can call &sin(3.1415)</td> <td valign="top">&nbsp</td> </tr> <tr> <td valign="top">sin(x), cos(x), tan(x)</td> <td valign="top">&sin($x), &cos($x), &tan($x)</td> <td valign="top">Trigonometric functions where x is in radians. $x can be a pure number, i.e., you can call &sin(3.1415)</td> <td valign="top">&nbsp</td> </tr> <tr> <td valign="top">asin(x), acos(x), atan(x), atan2(y,x)</td> <td valign="top">&asin($x), &acos($x), &atan($x), &atan2($y,$x)</td> <td valign="top">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 $y can be pure numbers</td> <td valign="top"> </td> </tr> <tr> <td valign="top">log(x), log10(x)</td> <td valign="top">&log($x), &log10($x)</td> <td valign="top">Natural and base-10 logarithm. $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">exp(x), pow(x,y), sqrt(x)</td> <td valign="top">&exp($x), &pow($x,$y), &sqrt($x)</td> <td valign="top">Exponential, power and square root, i.e.,ex, xy and /x. $x and $y can be pure numbers</td> <td valign="top"> </td> </tr> <tr> <td valign="top">abs(x), sgn(x)</td> <td valign="top">&abs($x), &sgn($x)</td> <td valign="top">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. $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">erf(x), erfc(x)</td> <td valign="top">&erf($x), &erfc($x)</td> <td valign="top">Error function.  erf = 2/sqrt(pi) integral (0,x) et-sq and erfx(x) = 1.0 - erf(x).  $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">ceil(x), floor(x)</td> <td valign="top">&ceil($x), &floor($x)</td> <td valign="top">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. $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">min(...), max(...)</td> <td valign="top">&min(...), &max(...)</td> <td valign="top">Returns the minimum/ maximum value of a list of arguments if the arguments are numbers. If the arguments are strings then it returns a string sorted according to the ASCII codes</td> <td valign="top"> </td> </tr> <tr> <td valign="top">factorial(n)</td> <td valign="top">&factorial($n)</td> <td valign="top">Argument (n) must be an integer else it will round down. The largest value for n is 170. $n can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">N%M</td> <td valign="top">$N%$M</td> <td valign="top">N and M are integers and returns the remainder (in integer) of N/M. $N and $M can be pure numbers</td> <td valign="top"> </td> </tr> <tr> <td valign="top">sinh(x), cosh(x), tanh(x)</td> <td valign="top">&sinh($x), &cosh($x), &tanh($x)</td> <td valign="top">Hyperbolic functions. $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">asinh(x), acosh(x), atanh(x)</td> <td valign="top">&asinh($x), &acosh($x), &atanh($x)</td> <td valign="top">Inverse hyperbolic functions. $x can be a pure number</td> <td valign="top"> </td> </tr> <tr> <td valign="top">roundto(x,n)</td> <td valign="top">&roundto($x,$n)</td> <td valign="top">Rounds a real number to n decimal points. $x and $n can be pure numbers</td> <td valign="top"> </td> </tr> <tr> <td valign="top">web("a","b","c") or web(a,b,c)</td> <td valign="top">&web("a","b","c") or &web($a,$b,$c)</td> <td valign="top">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</td> <td valign="top">&nbsp</td> </tr> <tr> <td valign="top">html("a") or html(a)</td> <td valign="top">&html("a") or &html($a)</td> <td valign="top">Output only if the output mode chosen is in html format</td> <td valign="top"> </td> </tr> <tr> <td valign="top">jn(m,x)</td> <td valign="top">&j0($x), &j1($x), &jn($m,$x), &jv($y,$x)</td> <td valign="top">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. $y can be a pure real number</td> <td valign="top">In CAPA, j0, j1 and jn are contained in one function, jn(m,x) where m takes the value of 0, 1 or 2. jv(y,x) is new to LON-CAPA.</td> </tr> <tr> <td valign="top">yn(m,x)</td> <td valign="top">&y0($x), &y1($x), &yn($m,$x), &yv($y,$x)</td> <td valign="top">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. $y can be a pure real number</td> <td valign="top">In CAPA, y0, y1 and yn are contained in one function, yn(m,x) where m takes the value of 0, 1 or 2. yv(y,x) is new to LON-CAPA.</td> </tr> <tr> <td valign="top">random(l,u,d)</td> <td valign="top">&random($l,$u,$d)</td> <td valign="top">Returns a uniformly distributed random number between the lower bound, l and upper bound, u in steps of d. $l, $u and $d can be pure numbers</td> <td valign="top">In CAPA, all the 3 arguments must be of the same type. However, now you can mix the type</td> </tr> <tr> <td valign="top">choose(i,...)</td> <td valign="top">&choose($i,...)</td> <td valign="top">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. $i can be a pure integer</td> <td valign="top"> </td> </tr> <tr> <td valign="top">map(seed;a,b,c,d;w,x,y,z)</td> <td valign="top">Option 1 - &map($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</td> <td valign="top">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.</td> <td valign="top">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.</td> </tr> <tr> <td valign="top">rmap(seed;a,b,c,d;w,x,y,z)</td> <td valign="top">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</td> <td valign="top">The rmap functions does the reverse action of map if the same seed is used in calling map and rmap. </td> <td valign="top">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.</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">$a=&xmlparse($string) </td> <td valign="top">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.</td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">tex(a,b), tex("a","b")</td> <td valign="top">&tex($a,$b), &tex("a","b")</td> <td valign="top">Returns a if the output mode is in tex otherwise returns b</td> <td valign="top"> </td> </tr> <tr> <td valign="top">var_in_tex(a)</td> <td valign="top">&var_in_tex($a)</td> <td valign="top">Equivalent to tex("a","")</td> <td valign="top"> </td> </tr> <tr> <td valign="top">to_string(x), to_string(x,y)</td> <td valign="top">&to_string($x), &to_string($x,$y)</td> <td valign="top">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.</td> <td valign="top"> </td> </tr> <tr> <td valign="top">capa_id(), class(), section(), set(), problem()</td> <td valign="top">&class(), &section()</td> <td valign="top">Returns null string, class descriptive name, section number, set number and null string.</td> <td valign="top">capa_id(), set() and problem() are no longer used. Currently, they return a null value.</td> </tr> <tr> <td valign="top">name(), student_number()</td> <td valign="top">&name(), &student_number()</td> <td valign="top">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.</td> <td valign="top"> </td> </tr> <tr> <td valign="top">open_date(), due_date(), answer_date()</td> <td valign="top">&open_date(), &due_date(), &answer_date()</td> <td valign="top">Problem open date, due date and answer date. The time is also included in 24-hr format.</td> <td valign="top">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.</td> </tr> <tr> <td valign="top">get_seed(), set_seed()</td> <td valign="top">Not implemented</td> <td valign="top">Get and set the random seed.</td> <td valign="top"> </td> </tr> <tr> <td valign="top">sub_string(a,b,c)</td> <td valign="top">&sub_string($a,$b,$c) perl  substr function. However, note the differences</td> <td valign="top">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 $result is "come"</td> <td valign="top">Perl intrinsic function, substr(string,b,c) starts counting from 0 (as opposed to 1). In the example to the left, substr($a,4,4) returns "ome ".</td> </tr> <tr> <td valign="top">array[xx]</td> <td valign="top">@arrayname Array is intrinsic in perl. To access a specific element use $arrayname[$n] where $n is the $n+1 element since the array count starts from 0</td> <td valign="top">"xx" can be a variable or a calculation.</td> <td valign="top">In LON-CAPA, an array is defined by @arrayname. It is not necessary to specify the dimension of the array. </td> </tr> <tr> <td valign="top">array_moments(B,A)</td> <td valign="top">@B=&array_moments(@A)</td> <td valign="top">Evaluates the moments of an array A and place the result in array B[i] where i = 0 to 4. The contents of B are as follows: B[0] = number of elements, B[1] = mean, B[2] = variance, B[3] = skewness and B[4] = kurtosis.</td> <td valign="top">In CAPA, the moments are passed as an array in the first argument whereas in LON-CAPA, the array containing the moments are set equal to the function.</td> </tr> <tr> <td valign="top">array_max(Name), array_min(Name)</td> <td valign="top">&min(@Name), &max(@Name)</td> <td valign="top">In LON-CAPA to find the maximum value of an array, use &max(@arrayname)  and to find the minimum value of an array, use &min(@arrayname)</td> <td valign="top">Combined with the min and max functions defined earlier.</td> </tr> <tr> <td valign="top">init_array(Name)</td> <td valign="top">undef @name</td> <td valign="top">To destroy the contents of an array, use</td> <td valign="top">Use perl intrinsic undef function.</td> </tr> <tr> <td valign="top">random_normal (return_array,item_cnt,seed,av,std_dev)</td> <td valign="top">@return_array=&random_normal ($item_cnt,$seed,$av,$std_dev)</td> <td valign="top">Generate $item_cnt deviates of normal distribution of average $av and standard deviation $std_dev. The distribution is generated from seed $seed</td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_beta (return_array,item_cnt,seed,aa,bb)</td> <td valign="top">@return_array=&random_beta ($item_cnt,$seed,$aa,$bb) NOTE: Both $aa and $bb MUST be greater than 1.0E-37.</td> <td valign="top">Generate $item_cnt deviates of beta distribution. The density of beta is: X^($aa-1) *(1-X)^($bb-1) /B($aa,$bb) for 0<X<1.</td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_gamma (return_array,item_cnt,seed,a,r)</td> <td valign="top">@return_array=&random_gamma ($item_cnt,$seed,$a,$r) NOTE: Both $a and $r MUST be positive.</td> <td valign="top">Generate $item_cnt deviates of gamma distribution. The density of gamma is: ($a**$r)/gamma($r) * X**($r-1) * exp(-$a*X).</td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_exponential (return_array,item_cnt,seed,av)</td> <td valign="top">@return_array=&random_exponential ($item_cnt,$seed,$av) NOTE: $av MUST be non-negative.</td> <td valign="top">Generate $item_cnt deviates of exponential distribution. </td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_poisson (return_array,item_cnt,seed,mu)</td> <td valign="top">@return_array=&random_poisson ($item_cnt,$seed,$mu) NOTE: $mu MUST be non-negative.</td> <td valign="top">Generate $item_cnt deviates of poisson distribution. </td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_chi (return_array,item_cnt,seed,df)</td> <td valign="top">@return_array=&random_chi ($item_cnt,$seed,$df) NOTE: $df MUST be positive.</td> <td valign="top">Generate $item_cnt deviates of chi_square distribution with $df degrees of freedom. </td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">random_noncentral_chi (return_array,item_cnt,seed,df,nonc)</td> <td valign="top">@return_array=&random_noncentral_chi ($item_cnt,$seed,$df,$nonc) NOTE: $df MUST be at least 1 and $nonc MUST be non-negative.</td> <td valign="top">Generate $item_cnt deviates of noncentral_chi_square distribution with $df degrees of freedom and noncentrality parameter $nonc. </td> <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA the results are set equal to the function.</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_f ($item_cnt,$seed,$dfn,$dfd) NOTE: Both $dfn and $dfd MUST be positive.</td> <td valign="top">Generate $item_cnt deviates of F (variance ratio) distribution with degrees of freedom $dfn (numerator) and $dfd (denominator). </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_noncentral_f ($item_cnt,$seed,$dfn,$dfd,$nonc) NOTE: $dfn must be at least 1, $dfd MUST be positive, and $nonc must be non-negative.</td> <td valign="top">Generate $item_cnt deviates of noncentral F (variance ratio) distribution with degrees of freedom $dfn (numerator) and $dfd (denominator). $nonc is the noncentrality parameter. </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_multivariate_normal ($item_cnt,$seed,@mean,@covar) NOTE: @mean should be a length p array of real numbers. @covar should be a length p array of references to length p arrays or real numbers (i.e. a p by p matrix.</td> <td valign="top">Generate $item_cnt deviates of multivariate_normal distribution with mean vector @mean and variance-covariance matrix. </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_multinomial ($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.</td> <td valign="top">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 $item_cnt.</td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_permutation ($item_cnt,@array) </td> <td valign="top">Returns @array randomly permuted.</td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_uniform ($item_cnt,$seed,$low,$high) NOTE: $low must be less than or equal to $high.</td> <td valign="top">Generate $item_cnt deviates from a uniform distribution. </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_uniform_integer ($item_cnt,$seed,$low,$high) NOTE: $low and $high are both passed through int(). $low must be less than or equal to $high.</td> <td valign="top">Generate $item_cnt deviates from a uniform distribution in integers. </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_binomial ($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.</td> <td valign="top">Generate $item_cnt deviates from the binomial distribution with $nt trials and the probabilty of an event in each trial is $p. </td> <td valign="top">New to LON-CAPA</td> </tr> <tr> <td valign="top">NOT IMPLEMENTED IN CAPA</td> <td valign="top">@return_array=&random_negative_binomial ($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.</td> <td valign="top">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. </td> <td valign="top">New to LON-CAPA</td> </tr> </table>  <h2><script> Variables</h2> <ul> <li> $external::target - set to the current target the xml parser is parsing for </li> <li> $external::part - set to the id of the current problem <part>; zero if there are now <part> </li> <li> $external::gradestatus - set to the value of the current resource.partid.solved value </li> <li> $external::datestatus - set to the current status of the clock either CLOSED, CAN_ANSWER, CANNOT_ANSWER, or SHOW_ANSWER </li> <li> $external::randomseed - set to the number that was used to seed the random number generator </li> <li>$pi - set to PI </li> <li>$rad2deg - converts radians to degrees </li> <li>$deg2rad - converts degrees to radians </li> </ul> <hr> <address><a href="mailto:albertel@marvin.lite.msu.edu">Guy Albertelli</a></address>   Last modified: Fri Jul 13 12:10:52 EDT 2001  </body> </html>