Annotation of doc/homework/homework5.html, revision 1.8
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4: <title>LON-CAPA Homework System</title>
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1.1 albertel 8: <h1>LON-CAPA Homework System</h1>
9:
10: <h2>Tags</h2>
11: <ul>
12: <li>
13: Response tags
14: <p>
15: Arguments for all response tags
16: </p>
17: <ul>
18: <li>
19: <i>ID</i>, if this isn't set it will be set during
20: the publication step. It is used to assign parameters names
21: in a way that can be tracked if an instructor modifies
22: things by hand.
23: </li>
24: <li>
25: <i>name</i> optional, if set, it will be used by the
26: resource assembly tool when one is modifying parameters.
27: </li>
28: </ul>
29: <p>
30: Implemented response tags
31: </p>
32: <ul>
33: <li>
1.2 albertel 34: <b><responseparam></b> if it appears it should be
35: inside of a <*response> tag, defines an externally
36: adjustable parameter for this question. Arguments:
37: <ul>
38: <li>
39: <i>default</i> required, specifies a default value for
40: the parameter
41: </li>
42: <li>
43: <i>name</i> required, specifies an internal name for
44: the parameter
45: </li>
46: <li>
47: <i>type</i> required specifies the type of parameter,
48: one of "tolerance", "int", "float", "string", "date"
49: (configuration of paramters is handled by
50: lonparmset.pm and parameter.html)
51: </li>
52: <li>
53: <i>description</i> a string describing the parameter,
54: this is what is used to talk about a parameter outside
55: of a problem
56: </li>
57: </ul>
58: </li>
59: <li>
1.1 albertel 60: <b><numericalresponse></b> implements a numerical
61: answer, it needs an internal <b><textline></b> for
62: the response to go in. It checks all styles of numerical
63: supported in CAPA. Possible args are:
64: <ul>
1.8 ! albertel 65: <li><i>answer</i> required, specifies the correct answer, may be either a perl list or scalar</li>
1.1 albertel 66: <li><i>units</i> optional, specifies unit of correct answer, CAPA style</li>
67: </ul>
68: </li>
69: <li>
1.8 ! albertel 70: <b><stringresponse></b> implements a string answer,
! 71: it needs an internal <b><textline></b> for the
! 72: response to go in. It can check the string for either case
! 73: or order.
! 74: <ul>
! 75: <li><i>answer</i> required, specifies the correct answer, may be either a perl list or scalar</li>
! 76: <li><i>type</i> optional, CAPA style str args, cs/ci/mc
! 77: <ul>
! 78: <li>cs - case senesitive, order important</li>
! 79: <li>ci - case insenesitive, order important</li>
! 80: <li>mc - case insenesitive, order unimportant</li>
! 81: </ul>
! 82: </li>
! 83: </ul>
! 84: <li>
1.1 albertel 85: <b><essayresponse></b> implements a ungraded large
86: text response, it need an internal <b><textarea></b>
87: for the response to go in.
88: </li>
89: <li>
90: <b><imageresponse></b> implements a image click
91: style image submission, uses the foil structure tags <a
92: href="#foil">below</a>. Additional tags that should appear
93: in a <foil> are:
94: <ul>
95: <li><b><image></b> required, the contained text
96: specifies a published graphical resource that is the
97: image used, should only appear once per foil</li>
98: <li><b><rectangle></b> required, the contained text
99: specifies a rectangular area that is correct, should
100: look like (1,2)-(3,4), at least 1 required</li>
101: <li><b><text></b> required, the contained text is
102: printed on top of the image.</li>
103: </ul>
104: </li>
105: <li>
106: <b><optionresponse></b> implements a "select from
107: these choices" style question, the choices are specified
108: by the instructor, it uses the foil structure tags <a
109: href="#foil">below</a> with this additional args:
110: <ul>
111: <li>
112: <b><foilgroup></b> is required to have
113: <i>options</i> which should be a perl list of possible
114: options for the student.
115: </li>
116: </ul>
117: </li>
118: <li>
119: <b><radiobuttonresponse></b> implements a true / false
120: style question with 1 correct answer.it uses the foil
121: structure tags <a href="#foil">below</a> but the
122: <i>value</i> of a <foil>can only be "true" or
123: "false" or "unused"
124: </li>
125: </ul>
126: <li>
127: <a name="foil">Foil Structure Tags</a>
128: <p>
129: All tags that implement a foil structure have an optional
130: arg of <i>max</i> that controls the maximum number of total
131: foils to show.
132: </p>
133: <ul>
134: <li>
135: <b><foilgroup></b> required, must be the tag that
136: surrounds all foil definitions
137: </li>
138: <li>
139: <b><foil></b> required, all data inside is a possible foil
140: </li>
141: <li>
142: <b><conceptgroup></b> optional, surrounds a
143: collection of <foil>, when a problem is displayed
144: only one of the contained <foil>is selected for
145: display. It receives one required argument
146: <i>concept</i>.
147: </li>
148: </ul>
149: </li>
150: <li>
151: Hint structure
152: <p>
153: All of these tags must appear inside a <b><*response></b> tag.
154: </p>
155: <ul>
156: <li>
157: <b><hintgroup></b> Tag that surrounds all of a hint.
158: </li>
159: <li>
160: <b><hintpart></b> required, Tag to implement
161: conditional hints. It has a required argument
162: <i>on</i>. When a <*hint> tag named the same as the
163: value the </i>on</i> attribute evaluates to be correct the
164: <hintpart> will show. If no other <hintpart>
165: are to show then all hintparts with a <i>on</i> of
166: "default" will show
167: </li>
168: <li>
169: <b><numericalhint></b> has all the arguments that
170: <numericalresponse>, does and the required attribute
171: <i>name</i> which should be set to the value of which
172: <hintpart> will be shown.
173: </li>
174: </ul>
175: </li>
176: <li>
177: Input Tags
178: <p>
179: This group of tags implement a mechanism for getting data
180: for students, they will usually be used by a
181: <*response>.
182: </p>
183: <ul>
184: <li>
185: <b><textarea></b> creates a Large text input box, If
186: data appears between the start and end tags, the data will
187: appear i the textarea if the student has not yet made a
188: submission. Additionally it takes two arguments <i>rows</i>
189: and <i>cols</i> which control the height and width of the
190: area respectively. It defaults to 10 and 80.
191: </li>
192: <li>
193: <b><textline></b> creates a single line of input
194: element, it accepts 1 argument <i>size</i> which controls
195: the width on the textline, it defaults to 20.
196: </li>
197: </ul>
198: </li>
199: <li>
200: Output Tags
201: <p>
202: This group of tags generate useful pieces of output.
203: </p>
204: <ul>
205: <li>
206: <b><displayduedate></b> this will insert the current
207: duedate if one is set into the document. It is generated
208: to be inside a table of 1x1 elements
209: </li>
210: <li>
211: <b><displaytitle></b> this will insert the title of
212: the problem from the metadata of the problem
213: </li>
214: <li>
215: <b><window></b> the text in between is put in a
216: popup javascript window
217: </li>
218: </ul>
219: </li>
220: <li>
221: Scripting
222: <p>
223: These tags allow the document to behave programatically
224: </p>
225: <ul>
226: <li>
227: <b><display></b> the intervening perl script is
228: evaluated in the safe space and the return value of the
229: script replaces the entire tag
230: </li>
231: <li>
232: <b><import></b> causes the parse to read in the file
233: named in the body of the tag and parse it as if the entire
234: text of the file had existed at location of the tag
235: </li>
236: <li>
237: <b><parserlib></b> the enclosed filename contains
238: definitions for new tags
239: </li>
240: <li>
241: <b><script></b> if the argument <i>type</i> is set
242: to "loncapa/perl" the enclosed data is a perl script which
243: is evaluated inside the perl Safe space. The return value
244: of the script is ignored.
245: </li>
246: <li>
247: <b><scriptlib></b> the enclosed filename contains
248: perl code to run in the safe space
249: </li>
250: <li>
251: <b><block></b> has a required argument
252: <i>condition</i> that is evaluated, it the condition is
253: true everything inside the tag is evaluated, if it is false
254: everything inside the block tag is skipped
255: </li>
256: <li>
257: <b><notsolved></b> everything inside the tag is
258: skipped if the problem is "solved"
259: </li>
260: <li>
261: <b><postanswerdate></b> everything inside the tag is
262: skipped if the problem is before the answer date
263: </li>
264: <li>
265: <b><preduedate></b> everything inside the tag is
266: skipped if the problem is after the due date
267: </li>
268: <li>
269: <b><randomlist></b> the enclosed tags are parsed in
270: a stable random order
271: </li>
272: <li>
273: <b><solved></b> everything inside the tag is
274: skipped if the problem is "not solved"
275: </li>
276: <li>
277: <b><while></b> implements a while loop, required
278: argument <i>condition</i> is a perl scriptlet that when
279: evaluated results in a true or false value, on true the
280: entirety of the text between the whiles is parsed. The
281: condition is tested again, etc. If false it goes to the
282: next node in the parse.
283: </li>
284: </ul>
285: </li>
286: <li>
287: Structure Tags
288: <p>
289: These tags give the problem a structure and take care of the
290: recording of data and giving the student messages.
291: </p>
292: <ul>
293: <li>
294: <b><problem></b> must be the first tag in the file,
295: this tag sets up the header of the webpage and generates
296: the submit buttons, it also handles due dates properly
297: </li>
298: <li>
299: <b><part></b> must be below <problem> if it is
300: going to be used. It does many of the same tasks as
301: <problem> but allows multiple separate problems to
302: exist in a single file.
303: </li>
304: <li>
305: <b><startouttext></b><b><endouttext></b> these
306: tags are somewhat special, they must have no internal text
307: and occur in pairs. Their use is to mark up the problem so
308: the web editor knows what sections should be edited in a
309: plain text block on the web.
310: </li>
311: </ul>
312: </li>
313: </ul>
314: <h2><script> Functions</h2>
315: <p>
316: A list of functions that have been written that are available in
1.5 ng 317: the Safe space scripting environment inside a problem.
1.1 albertel 318: </p>
319: <ul>
1.3 ng 320: <li>sin(x), cos(x), tan(x)</li>
321: <li>asin(x), acos(x), atan(x), atan2(y,x)</li>
322: <li>log(x), log10(x)</li>
323: <li>exp(), pow(x,y), sqrt(x)</li>
324: <li>abs(x), sgn(x)</li>
325: <li>erf(x), erfc(x)</li>
326: <li>ceil(x), floor(x)</li>
327: <li>min(...), max(...)</li>
328: <li>factorial(n)</li>
329: <li>N%M</li>
330: <li>sinh(x), cosh(x), tanh(x)</li>
331: <li>asinh(x), acosh(x), atanh(x)</li>
332: <li>roundto(x,n)</li>
333: <li>web("a","b","c") or web(a,b,c)</li>
334: <li>html("a") or html(a)</li>
335: <li>j0(x), j1(x), jn(n,x), jv(y,x)</li>
336: <li>y0(x), y1(x), yn(n,x), yv(y,x)</li>
1.1 albertel 337: <li>random</li>
338: <li>choose</li>
1.3 ng 339: <li>tex("a","b") or tex(a,b)</li>
340: <li>var_in_tex(a)</li>
341: <li>to_string(x), to_string(x,y)</li>
342: <li>class(), section()</li>
343: <li>name(), student_number()</li>
344: <li>open_date(), due_date(), answer_date()</li>
345: <li>sub_string()</li>
346: <li>array_moments(array)</li>
347: <li>format(x,y)</li>
348: <li>map(...)</li>
1.1 albertel 349: <li>caparesponse_check</li>
350: <li>caparesponse_check_list</li>
351: </ul>
1.5 ng 352: <!-- Table inserted by H. K. Ng
353: 06/01/2001
354: 06/12/2001
355: -->
356: <p>
357: Detailed descriptions of each function and comparison with CAPA.
358: </p>
1.4 ng 359:
360: <table border=1>
361: <tr>
362: <td valign="top"><b>CAPA Functions</b</td>
363: <td valign="top"><b>LON-CAPA</b</td>
364: <td valign="top"><b>Descriptions</b</td>
365: <td valign="top"><b>Differences (if any)</b</td>
366: </tr>
367:
368: <tr>
369: <td valign="top">sin(x), cos(x), tan(x)</td>
370: <td valign="top">&sin($x), &cos($x), &tan($x)</td>
371: <td valign="top">Trigonometric functions where x is in radians. $x
372: can be a pure number, i.e., you can call &sin(3.1415)</td>
373: <td valign="top"> </td>
374: </tr>
375:
376: <tr>
377: <td valign="top">sin(x), cos(x), tan(x)</td>
378: <td valign="top">&sin($x), &cos($x), &tan($x)</td>
379: <td valign="top">Trigonometric functions where x is in radians. $x
380: can be a pure number, i.e., you can call &sin(3.1415)</td>
381: <td valign="top"> </td>
382: </tr>
383:
384: <tr>
385: <td valign="top">asin(x), acos(x), atan(x), atan2(y,x)</td>
386: <td valign="top">&asin($x), &acos($x), &atan($x), &atan2($y,$x)</td>
387: <td valign="top">Inverse trigonometric functions. Return value is
388: in radians. For asin and acos the value of x must be between -1 and 1.
389: The atan2 returns a value between -pi and pi the sign of which is determined
390: by y. $x and $y can be pure numbers</td>
391: <td valign="top"> </td>
392: </tr>
393:
394: <tr>
395: <td valign="top">log(x), log10(x)</td>
396: <td valign="top">&log($x), &log10($x)</td>
397: <td valign="top">Natural and base-10 logarithm. $x can be a pure number</td>
398: <td valign="top"> </td>
399: </tr>
400:
401: <tr>
402: <td valign="top">exp(x), pow(x,y), sqrt(x)</td>
403: <td valign="top">&exp($x), &pow($x,$y), &sqrt($x)</td>
404: <td valign="top">Exponential, power and square root, i.e.,e<sup>x</sup>, x<sup>y</sup> and /x. $x and $y can be pure numbers</td>
405:
406: <td valign="top"> </td>
407: </tr>
408:
409: <tr>
410: <td valign="top">abs(x), sgn(x)</td>
411: <td valign="top">&abs($x), &sgn($x)</td>
412: <td valign="top">Abs takes the absolute value of x while sgn(x) returns
413: 1, 0 or -1 depending on the value of x. For x>0, sgn(x) = 1, for x=0, sgn(x)
414: = 0 and for x<0, sgn(x) = -1. $x can be a pure number</td>
415: <td valign="top"> </td>
416: </tr>
417:
418: <tr>
419: <td valign="top">erf(x), erfc(x)</td>
420: <td valign="top">&erf($x), &erfc($x)</td>
421: <td valign="top">Error function. erf = 2/sqrt(pi) integral (0,x) e<sup>t-sq</sup> and <i> erfx(x)</i> = 1.0 - <i>erf(x)</i>. $x can be a pure number</td>
422: <td valign="top"> </td>
423: </tr>
424:
425: <tr>
426: <td valign="top">ceil(x), floor(x)</td>
427: <td valign="top">&ceil($x), &floor($x)</td>
428: <td valign="top">Ceil function returns an integer rounded up whereas
429: floor function returns and integer rounded down. If x is an integer than
430: it returns the value of the integer. $x can be a pure number</td>
431: <td valign="top"> </td>
432: </tr>
433:
434: <tr>
435: <td valign="top">min(...), max(...)</td>
436: <td valign="top">&min(...), &max(...)</td>
437: <td valign="top">Returns the minimum/ maximum value of a list of
438: arguments if the arguments are numbers. If the arguments are strings then
439: it returns a string sorted according to the ASCII codes</td>
440: <td valign="top"> </td>
441: </tr>
442:
443: <tr>
444: <td valign="top">factorial(n)</td>
445: <td valign="top">&factorial($n)</td>
446: <td valign="top">Argument (n) must be an integer else it will round
447: down. The largest value for n is 170. $n can be a pure number</td>
448: <td valign="top"> </td>
449: </tr>
450:
451: <tr>
452: <td valign="top">N%M</td>
453: <td valign="top">$N%$M</td>
454:
455: <td valign="top">N and M are integers and returns the remainder (in
456: integer) of N/M. $N and $M can be pure numbers</td>
457: <td valign="top"> </td>
458: </tr>
459:
460: <tr>
461: <td valign="top">sinh(x), cosh(x), tanh(x)</td>
462: <td valign="top">&sinh($x), &cosh($x), &tanh($x)</td>
463: <td valign="top">Hyperbolic functions. $x can be a pure number</td>
464: <td valign="top"> </td>
465: </tr>
466:
467: <tr>
468: <td valign="top">asinh(x), acosh(x), atanh(x)</td>
469: <td valign="top">&asinh($x), &acosh($x), &atanh($x)</td>
470: <td valign="top">Inverse hyperbolic functions. $x can be a pure number</td>
471: <td valign="top"> </td>
472: </tr>
473:
474: <tr>
475: <td valign="top">roundto(x,n)</td>
476: <td valign="top">&roundto($x,$n)</td>
477: <td valign="top">Rounds a real number to n decimal points. $x and
478: $n can be pure numbers</td>
479: <td valign="top"> </td>
480: </tr>
481:
482: <tr>
483: <td valign="top">web("a","b","c") or web(a,b,c)</td>
484: <td valign="top">&web("a","b","c") or &web($a,$b,$c)</td>
485: <td valign="top">Returns either a, b or c depending on the output
486: medium. a is for plain ASCII, b for tex output and c for html output</td>
487: <td valign="top"> </td>
488: </tr>
489:
490: <tr>
491: <td valign="top">html("a") or html(a)</td>
492: <td valign="top">&html("a") or &html($a)</td>
493: <td valign="top">Output only if the output mode chosen is in html
494: format</td>
495: <td valign="top"> </td>
496: </tr>
497:
498: <tr>
499: <td valign="top">jn(m,x)</td>
500: <td valign="top">&j0($x), &j1($x), &jn($m,$x), &jv($y,$x)</td>
501: <td valign="top">Bessel functions of the first kind with orders 0,
502: 1 and m respectively. For jn(m,x), m must be an integer whereas for jv(y,x),
503: y is real. $x can be a pure number. $m must be an integer and can be a
504: pure integer number. $y can be a pure real number</td>
505: <td valign="top">In CAPA, j0, j1 and jn are contained in one function,
1.5 ng 506: jn(m,x) where m takes the value of 0, 1 or 2. jv(y,x) is new to LON-CAPA.</td>
1.4 ng 507: </tr>
508:
509: <tr>
510: <td valign="top">yn(m,x)</td>
511: <td valign="top">&y0($x), &y1($x), &yn($m,$x), &yv($y,$x)</td>
512: <td valign="top">Bessel functions of the second kind with orders
513: 0, 1 and m respectively. For yn(m,x), m must be an integer whereas for
514: yv(y,x), y is real. $x can be a pure number. $m must be an integer and
515: can be a pure integer number. $y can be a pure real number</td>
516: <td valign="top">In CAPA, y0, y1 and yn are contained in one function,
1.5 ng 517: yn(m,x) where m takes the value of 0, 1 or 2. yv(y,x) is new to LON-CAPA.</td>
1.4 ng 518: </tr>
519:
520: <tr>
521: <td valign="top">random(l,u,d)</td>
522: <td valign="top">&random($l,$u,$d)</td>
523: <td valign="top">Returns a uniformly distributed random number between
524: the lower bound, l and upper bound, u in steps of d. $l, $u and $d can
525: be pure numbers</td>
526: <td valign="top">In CAPA, all the 3 arguments must be of the same
527: type. However, now you can mix the type</td>
528: </tr>
529:
530: <tr>
531: <td valign="top">choose(i,...)</td>
532: <td valign="top">&choose($i,...)</td>
533: <td valign="top">Choose the ith item from the argument list. i must
534: be an integer greater than 0 and the value of i should not exceed the number
535: of items. $i can be a pure integer</td>
536: <td valign="top"> </td>
537: </tr>
538:
539: <tr>
1.6 ng 540: <td valign="top">map(seed;a,b,c,d;w,x,y,z)</td>
1.7 ng 541: <td valign="top">Option 1 - &map($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) or <br>
542: Option 2 - &map($seed,\@mappedArray,[$a,$b,$c,$d]) <br>
543: Option 3 - @mappedArray = &map($seed,[$a,$b,$c,$d]) <br>
544: Option 4 - ($w,$x,$y,$z) = &map($seed,\@a) <br>
545: where $a='A'<br>
546: $b='B'<br>
547: $c='B'<br>
548: $d='B'<br>
549: $w, $x, $y, and $z are variables</td>
1.6 ng 550: <td valign="top">Assigns to the variables $w, $x, $y and $z the values of the
1.7 ng 551: $a, $b, $c and $c (A, B, C and D). The precise value for $w .. depends
552: on the seed. (Option 1 of calling map).
553: In option 2, the values of $a, $b .. are mapped into the array, @mappedArray. The two
554: options illustrate the different grouping. Options 3 and 4 give a consistent
555: way (with other functions) of mapping the items. For each option, the group can
556: be passed as an array, for example, [$a,$b,$c,$d] => \@a.</td>
1.6 ng 557: <td valign="top">In CAPA, the arguments are divided into three groups separated
558: by a semicolon ;. In LON-CAPA, the separation is done by using [] brackets or
559: using an array @a. Note the backslash (\) before the arguments in the
560: second and third groups.</td>
561: </tr>
562:
563:
564: <tr>
565: <td valign="top">rmap(seed;a,b,c,d;w,x,y,z)</td>
1.7 ng 566: <td valign="top">Option 1 - &rmap($seed,[\$w,\$x,\$y,\$z],[$a,$b,$c,$d]) or <br>
567: Option 2 - &rmap($seed,\@rmappedArray,[$a,$b,$c,$d]) <br>
568: Option 3 - @rmapped_array = &rmap($seed,[$a,$b,$c,$d]) <br>
569: Option 4 - ($w,$x,$y,$z) = &rmap($seed,\@a) <br>
570: where $a='A'<br>
571: $b='B'<br>
572: $c='B'<br>
573: $d='B'<br>
574: $w, $x, $y, and $z are variables</td>
1.6 ng 575: <td valign="top">The rmap functions does the reverse action of map if the same seed
576: is used in calling map and rmap. </td>
577: <td valign="top">In CAPA, the arguments are divided into three groups separated
578: by a semicolon ;. In LON-CAPA, the separation is done by using [] brackets or
579: using an array @a. Note the backslash (\) before the arguments in the
580: second and third groups.</td>
581: </tr>
1.8 ! albertel 582:
! 583: <tr>
! 584: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
! 585: <td valign="top">$a=&xmlparse($string) </td>
! 586: <td valign="top">Runs the internal parser over the
! 587: argument parsing for display. <b>Warning</b> This will
! 588: result in different strings in different targets. Don't use
! 589: the results of this function as an answer.</td>
! 590: <td valign="top">New to LON-CAPA</td>
! 591: </tr>
1.6 ng 592:
593: <tr>
1.4 ng 594: <td valign="top">tex(a,b), tex("a","b")</td>
595: <td valign="top">&tex($a,$b), &tex("a","b")</td>
596: <td valign="top">Returns a if the output mode is in tex otherwise
597: returns b</td>
598: <td valign="top"> </td>
599: </tr>
600:
601: <tr>
602: <td valign="top">var_in_tex(a)</td>
603: <td valign="top">&var_in_tex($a)</td>
604: <td valign="top">Equivalent to tex("a","")</td>
605: <td valign="top"> </td>
606: </tr>
607:
608: <tr>
609: <td valign="top">to_string(x), to_string(x,y)</td>
610: <td valign="top">&to_string($x), &to_string($x,$y)</td>
611: <td valign="top">If x is an integer, returns a string. If x is real
612: than the output is a string with format given by y. For example, if x =
613: 12.3456, &to_string(x,".3F") = 12.345 and &to_string(x,".3E") =
614: 1.234E+01.</td>
615: <td valign="top"> </td>
616: </tr>
617:
618: <tr>
619: <td valign="top">capa_id(), class(), section(), set(), problem()</td>
620: <td valign="top">&class(), &section()</td>
621: <td valign="top">Returns null string, class descriptive name, section
622: number, set number and null string.</td>
623: <td valign="top">capa_id(), set() and problem() are no longer used.
624: Currently, they return a null value.</td>
625: </tr>
626:
627: <tr>
628: <td valign="top">name(), student_number()</td>
629: <td valign="top">&name(), &student_number()</td>
630: <td valign="top">Return the full name in the following format: lastname,
631: firstname initial. Student_number returns the student 9-alphanumeric string.
632: If undefined, the functions return null.</td>
633: <td valign="top"> </td>
634: </tr>
635:
636: <tr>
637: <td valign="top">open_date(), due_date(), answer_date()</td>
638: <td valign="top">&open_date(), &due_date(), &answer_date()</td>
639: <td valign="top">Problem open date, due date and answer date. The
640: time is also included in 24-hr format.</td>
641: <td valign="top">Output format for time is changed slightly. If pass
642: noon, it displays ..pm else it displays ..am. So 23:59 is displayed as
643: 11:59 pm.</td>
644: </tr>
645:
646: <tr>
647: <td valign="top">get_seed(), set_seed()</td>
648: <td valign="top">Not implemented</td>
649: <td valign="top">Get and set the random seed.</td>
650: <td valign="top"> </td>
651: </tr>
652:
653: <tr>
654: <td valign="top">sub_string(a,b,c)</td>
655: <td valign="top">&sub_string($a,$b,$c) <br>perl substr function.
656: However, note the differences</td>
657: <td valign="top">Retrieve a portion of string a starting from b and
658: length c. For example, $a = "Welcome to LON-CAPA";
659: $result=&sub_string($a,4,4); then $result is "come"</td>
660: <td valign="top">Perl intrinsic function, substr(string,b,c) starts
661: counting from 0 (as opposed to 1). In the example to the left, substr($a,4,4)
662: returns "ome ".</td>
663: </tr>
664:
665: <tr>
666: <td valign="top">array[xx]</td>
667: <td valign="top">@arrayname <br>Array is intrinsic in perl.
668: To access a specific element use $arrayname[$n] where $n
669: is the $n+1 element since the array count starts from 0</td>
670: <td valign="top">"xx" can be a variable or a calculation.</td>
671: <td valign="top">In LON-CAPA, an array is defined by @arrayname.
672: It is not necessary to specify the dimension of the array. </td>
673: </tr>
674:
675: <tr>
676: <td valign="top">array_moments(B,A)</td>
677: <td valign="top">@B=&array_moments(@A)</td>
678: <td valign="top">Evaluates the moments of an array A and place the
679: result in array B[i] where i = 0 to 4. The contents of B are as follows:
680: B[0] = number of elements, B[1] = mean, B[2] = variance, B[3] = skewness
681: and B[4] = kurtosis.</td>
1.5 ng 682: <td valign="top">In CAPA, the moments are passed as an array in the first argument whereas
683: in LON-CAPA, the array containing the moments are set equal to the function.</td>
1.4 ng 684: </tr>
685:
686: <tr>
687: <td valign="top">array_max(Name), array_min(Name)</td>
688: <td valign="top">&min(@Name), &max(@Name)</td>
689: <td valign="top">In LON-CAPA to find the maximum value of an array, use
690: &max(@arrayname) and to find the minimum value of an array, use
691: &min(@arrayname)</td>
692: <td valign="top">Combined with the min and max functions defined
693: earlier.</td>
694: </tr>
695:
696: <tr>
697: <td valign="top">init_array(Name)</td>
698: <td valign="top">undef @name</td>
699: <td valign="top">To destroy the contents of an array, use</td>
700: <td valign="top">Use perl intrinsic undef function.</td>
701: </tr>
1.5 ng 702: <tr>
703: <td valign="top">random_normal (return_array,item_cnt,seed,av,std_dev)</td>
704: <td valign="top">@return_array=&random_normal ($item_cnt,$seed,$av,$std_dev)</td>
705: <td valign="top">Generate $item_cnt deviates of normal distribution of average $av and
706: standard deviation $std_dev. The distribution is generated from seed $seed</td>
707: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
708: the results are set equal to the function.</td>
709: </tr>
710: <tr>
711: <td valign="top">random_beta (return_array,item_cnt,seed,aa,bb)</td>
712: <td valign="top">@return_array=&random_beta ($item_cnt,$seed,$aa,$bb) <br>
713: NOTE: Both $aa and $bb MUST be greater than 1.0E-37.</td>
714: <td valign="top">Generate $item_cnt deviates of beta distribution.
715: The density of beta is:
716: X^($aa-1) *(1-X)^($bb-1) /B($aa,$bb) for 0<X<1.</td>
717: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
718: the results are set equal to the function.</td>
719: </tr>
720: <tr>
721: <td valign="top">random_gamma (return_array,item_cnt,seed,a,r)</td>
722: <td valign="top">@return_array=&random_gamma ($item_cnt,$seed,$a,$r) <br>
723: NOTE: Both $a and $r MUST be positive.</td>
724: <td valign="top">Generate $item_cnt deviates of gamma distribution.
725: The density of gamma is:
726: ($a**$r)/gamma($r) * X**($r-1) * exp(-$a*X).</td>
727: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
728: the results are set equal to the function.</td>
729: </tr>
730: <tr>
731: <td valign="top">random_exponential (return_array,item_cnt,seed,av)</td>
732: <td valign="top">@return_array=&random_exponential ($item_cnt,$seed,$av) <br>
733: NOTE: $av MUST be non-negative.</td>
734: <td valign="top">Generate $item_cnt deviates of exponential distribution. </td>
735: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
736: the results are set equal to the function.</td>
737: </tr>
738: <tr>
739: <td valign="top">random_poisson (return_array,item_cnt,seed,mu)</td>
740: <td valign="top">@return_array=&random_poisson ($item_cnt,$seed,$mu) <br>
741: NOTE: $mu MUST be non-negative.</td>
742: <td valign="top">Generate $item_cnt deviates of poisson distribution. </td>
743: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
744: the results are set equal to the function.</td>
745: </tr>
746: <tr>
747: <td valign="top">random_chi (return_array,item_cnt,seed,df)</td>
748: <td valign="top">@return_array=&random_chi ($item_cnt,$seed,$df) <br>
749: NOTE: $df MUST be positive.</td>
750: <td valign="top">Generate $item_cnt deviates of chi_square distribution with $df
751: degrees of freedom. </td>
752: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
753: the results are set equal to the function.</td>
754: </tr>
755: <tr>
756: <td valign="top">random_noncentral_chi (return_array,item_cnt,seed,df,nonc)</td>
757: <td valign="top">@return_array=&random_noncentral_chi ($item_cnt,$seed,$df,$nonc) <br>
758: NOTE: $df MUST be at least 1 and $nonc MUST be non-negative.</td>
759: <td valign="top">Generate $item_cnt deviates of noncentral_chi_square
760: distribution with $df
761: degrees of freedom and noncentrality parameter $nonc. </td>
762: <td valign="top">In CAPA the results are passed as the first argument whereas in LON-CAPA
763: the results are set equal to the function.</td>
764: </tr>
765: <tr>
766: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
767: <td valign="top">@return_array=&random_f ($item_cnt,$seed,$dfn,$dfd) <br>
768: NOTE: Both $dfn and $dfd MUST be positive.</td>
769: <td valign="top">Generate $item_cnt deviates of F (variance ratio) distribution with
770: degrees of freedom $dfn (numerator) and $dfd (denominator). </td>
771: <td valign="top">New to LON-CAPA</td>
772: </tr>
773: <tr>
774: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
775: <td valign="top">@return_array=&random_noncentral_f ($item_cnt,$seed,$dfn,$dfd,$nonc) <br>
776: NOTE: $dfn must be at least 1, $dfd MUST be positive, and $nonc must
777: be non-negative.</td>
778: <td valign="top">Generate $item_cnt deviates of noncentral F (variance ratio)
779: distribution with degrees of freedom $dfn (numerator) and $dfd (denominator).
780: $nonc is the noncentrality parameter. </td>
781: <td valign="top">New to LON-CAPA</td>
782: </tr>
783: <tr>
784: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
785: <td valign="top">@return_array=&random_multivariate_normal ($item_cnt,$seed,@mean,@covar) <br>
786: NOTE: @mean should be a length p array of real numbers. @covar should be a length
787: p array of references to length p arrays or real numbers (i.e. a p by p matrix.</td>
788: <td valign="top">Generate $item_cnt deviates of multivariate_normal distribution with
789: mean vector @mean and variance-covariance matrix. </td>
790: <td valign="top">New to LON-CAPA</td>
791: </tr>
792: <tr>
793: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
794: <td valign="top">@return_array=&random_multinomial ($item_cnt,$seed,@p) <br>
795: NOTE: $item_cnt is rounded with int() and the result must be non-negative.
796: The number of elements in @p must be at least 2.</td>
797: <td valign="top">Returns single observation from multinomial distribution with
798: $item_cnt events classified into as many categories as the length of @p.
799: The probability of an event being classified into category i is given by
800: ith element of @p. The observation is an array with length equal to @p, so
801: when called in a scalar context it returns the length of @p. The sum of the
802: elements of the obervation is equal to $item_cnt.</td>
803: <td valign="top">New to LON-CAPA</td>
804: </tr>
805: <tr>
806: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
807: <td valign="top">@return_array=&random_permutation ($item_cnt,@array) </td>
808: <td valign="top">Returns @array randomly permuted.</td>
809: <td valign="top">New to LON-CAPA</td>
810: </tr>
811: <tr>
812: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
813: <td valign="top">@return_array=&random_uniform ($item_cnt,$seed,$low,$high) <br>
814: NOTE: $low must be less than or equal to $high.</td>
815: <td valign="top">Generate $item_cnt deviates from a uniform distribution. </td>
816: <td valign="top">New to LON-CAPA</td>
817: </tr>
818: <tr>
819: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
820: <td valign="top">@return_array=&random_uniform_integer ($item_cnt,$seed,$low,$high) <br>
821: NOTE: $low and $high are both passed through int().
822: $low must be less than or equal to $high.</td>
823: <td valign="top">Generate $item_cnt deviates from a uniform distribution in integers. </td>
824: <td valign="top">New to LON-CAPA</td>
825: </tr>
826: <tr>
827: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
828: <td valign="top">@return_array=&random_binomial ($item_cnt,$seed,$nt,$p) <br>
829: NOTE: $nt is rounded using int() and the result must be non-negative.
830: $p must be between 0 and 1 inclusive.</td>
831: <td valign="top">Generate $item_cnt deviates from the binomial distribution with
832: $nt trials and the probabilty of an event in each trial is $p. </td>
833: <td valign="top">New to LON-CAPA</td>
834: </tr>
835: <tr>
836: <td valign="top">NOT IMPLEMENTED IN CAPA</td>
837: <td valign="top">@return_array=&random_negative_binomial ($item_cnt,$seed,$ne,$p) <br>
838: NOTE: $ne is rounded using int() and the result must be positive.
839: $p must be between 0 and 1 exclusive.</td>
840: <td valign="top">Generate an array of $item_cnt outcomes generated from
841: negative binomial distribution with
842: $ne events and the probabilty of an event in each trial is $p. </td>
843: <td valign="top">New to LON-CAPA</td>
1.4 ng 844: </tr>
1.5 ng 845: </table>
846: <!-- insertion ends -->
1.4 ng 847:
1.1 albertel 848: <h2><script> Variables</h2>
849: <ul>
850: <li>
851: $external::target - set to the current target the xml parser
852: is parsing for
853: </li>
854: <li>
855: $external::part - set to the <i>id</i> of the current problem
856: <part>; zero if there are now <part>
857: </li>
858: <li>
859: $external::gradestatus - set to the value of the current
860: resource.partid.solved value
861: </li>
862: <li>
863: $external::datestatus - set to the current status of the clock
864: either CLOSED, CAN_ANSWER, CANNOT_ANSWER, or SHOW_ANSWER
865: </li>
866: <li>
867: $external::randomseed - set to the number that was used to
868: seed the random number generator
869: </li>
870: <li>$pi - set to PI </li>
1.3 ng 871: <li>$rad2deg - converts radians to degrees </li>
872: <li>$deg2rad - converts degrees to radians </li>
1.1 albertel 873: </ul>
874:
875: <hr>
876: <address><a href="mailto:albertel@marvin.lite.msu.edu">Guy Albertelli</a></address>
877: <!-- Created: Thu May 17 15:05:35 EDT 2001 -->
878: <!-- hhmts start -->
1.8 ! albertel 879: Last modified: Fri Jul 13 12:10:52 EDT 2001
1.1 albertel 880: <!-- hhmts end -->
881: </body>
882: </html>
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