--- loncom/html/adm/help/tex/Problem_LON-CAPA_Functions.tex 2012/01/03 21:56:35 1.23
+++ loncom/html/adm/help/tex/Problem_LON-CAPA_Functions.tex 2018/06/06 18:40:08 1.34
@@ -47,6 +47,9 @@ erf = 2/sqrt(pi) integral (0,x) et-sq an
\&format(\$x,'nn') & Display or format \$x as nn where nn is nF or nE or nS and n is an integer. \\
\hline
+
+\$expr=\&math_calculus_expression() & Creates Math::Calculus::Expression object. Methods are: \$expr->addVariable('x'), \$expr->setExpression('f(x)'), \$expr->simplify, \$expr->getExpression -- see Math::Calculus::Expression documentation at cpan.org for details.\\
+\hline
\&prettyprint(\$x,'nn','optional target') & Note that that tag $<$num$>$ can be used to do the same thing. Display or format \$x as nn where nn is nF or nE or nS and n is an integer. Also supports the first character being a \$, it then will format the result with a a call to \&dollarformat() described below. If the first character is a , it will format it with commas grouping the thousands. In S mode it will fromat the number to the specified number of significant figures and display it in F mode. In E mode it will attempt to generate a pretty x10\^{}3 rather than a E3 following the number, the 'optional target' argument is optional but can be used to force \&prettyprint to generate either 'tex' output, or 'web' output, most people do not need to specify this argument and can leave it blank.\\
\hline
@@ -65,8 +68,8 @@ Option 4 - @all = \&languages($\backslas
\&roundto(\$x,\$n) & Rounds a real number to n decimal points. \$x and \$n can be pure numbers \\
\hline
-\&cas(\$s,\$e,\$l)&Evaluates the expression \$e inside the symbolic algebra system \$s. Currently, only the Maxima symbolic math system is implemented.
-\$l is an optional comma-separated list of libraries. Example: \&cas('maxima','6*7')\\
+\&cas(\$s,\$e,\$l)&Evaluates the expression \$e inside the symbolic algebra system \$s. Currently, the Maxima symbolic math system ('maxima') and the R statistical computing system ('R') are implemented.
+\$l is an optional comma-separated list of libraries. Example: \&cas('maxima','diff(sin(x)/cos(x),x,2)')\\
\hline
\&implicit\_multiplication(\$f)&Adds mathematical multiplication operators to the formula expression \$f where only implicit multiplication is used. Example: \&implicit\_multiplication('2(b+3c)') returns 2*(b+3*c) \\
@@ -84,7 +87,7 @@ Option 4 - @all = \&languages($\backslas
\&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 \\
\hline
-\&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 \\
+\&random(\$l,\$u,\$d) & Returns a uniformly distributed random number between the lower bound, l and upper bound, u in steps of d. d is optional. If omitted, a step of 1 is used. \$l, \$u and \$d can be pure numbers. \\
\hline
\&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 \\
@@ -133,7 +136,7 @@ Option 1 - \&map(\$seed,[$\backslash$\$w
\&name(), \&student\_number(), \&firstname(), \&middlename(), \&lastname() & Return the full name in the following format: lastname, firstname initial. Student\_number returns the student 9-alphanumeric string. The functions firstname, middlename, and lastname return just that part of the name. If undefined, the functions return null. \\
\hline
-\&check\_status(\$partid) &Returns a number identifying the current status of a part. True values mean that a part is ``done'' (either unanswerable because of tries exhaustion, or correct) or a false value if a part can still be attempted. If \$part is unspecified, it will check either the current $<$part$>$'s status or if outside of a $<$part$>$, check the status of previous $<$part$>$. The full set of return codes are: 'undef' means it is unattempted, 0 means it is attempted and wrong but still has tries, 1 means it is marked correct, 2 means they have exceed maximum number of tries, 3 means it after the answer date.\\
+\&check\_status(\$partid) &Returns a number identifying the current status of a part. True values mean that a part is ``done'': either unanswerable because of tries exhaustion, or fully correct, or only partially correct (and retries not permitted). A false value means that a part can still be attempted. If \$part is unspecified, it will check either the current $<$part$>$'s status or if outside of a $<$part$>$, check the status of previous $<$part$>$. The full set of return codes are: 'undef' means it is unattempted, 0 means it is attempted but still has tries, and is either wrong (or partially correct, retries allowed), 1 means it is fully correct or partially correct (no retries), 2 means they have exceeded maximum number of tries, 3 means it is after the answer date.\\
\hline
\&open\_date(\$partid), \&due\_date(\$partid), \&answer\_date(\$partid) & Problem open date, due date and answer date in local human-readable format. Part 0 is chosen if \$partid is omitted.\\
\hline
@@ -141,7 +144,20 @@ Option 1 - \&map(\$seed,[$\backslash$\$w
epoch (UTC), which can be used in calculations.\\
\hline
-\&submission(\$partid,\$responseid,\$version) & Returns what the student submitted for response \$responseid in part \$partid. You can get these IDs from the XML-code of the problem. \$version is optional and returns the \$version-th submission of the student that was graded.\\
+\&submission(\$partid,\$responseid,\$version,
+\$encode,\$cleanupnum,\$mapalias) & Returns what the student submitted for response \$responseid in part \$partid. You can get these IDs from the XML-code of the problem. Use 0 as \$partid for problems without parts. \$version is optional and returns the \$version-th submission of the student that was graded. If \$version is 0 or omitted, the latest submission is returned.
+\$encode is also optional and allows the author to explicitly encode the returned string. It's up to the author to take care of properly escaping all characters which might be interpreted by the browser.
+\$cleanupnum is also optional, and supports clean-up of the retrieved submission.
+It is a reference to a hash, with one or more of the following:
+exponent =$>$ 1,
+comma =$>$ 1,
+letterforzero =$>$ 1,
+spaces =$>$ 1,
+format =$>$ 'ns'
+(where n is an integer, i.e., number of significant digits). For example, to convert a student submission of
+11,300 to 11300 include \{ comma =$>$ 1, \} as the fifth arg.
+\$mapalias is also optional, and supports retrieval of the submission for a response item in a different problem in the course, for which a (unique) mapalias has been set.
+The default (mapalias not defined) is to retrieve the submission for the specified part and response IDs in the current problem.\\
\hline
\¶meter\_setting(\$name,\$partid) & Returns the parameter setting \$name. Partid is optional.\\
@@ -157,6 +173,10 @@ optional array of wrong answers that sho
Returns the ID of the current part.\\
\hline
+\&input\_id(part\_id, response\_id, textline\_id) &
+Returns the HTML id of the input field. This is useful in Javascript scripts to get a safe reference to a response textline field with \texttt{document.getElementById()}.\\
+\hline
+
Not implemented & Get and set the random seed. \\
\hline
@@ -240,3 +260,13 @@ undef @name & To destroy the contents o
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. \\
\hline
\end{longtable}
+
+The \&EXT() \index{\&EXT}external function is extremely powerful, and is used to access parameters
+and submission values. It can be
+used within scripts and also within cell formulas in the grading spreadsheet.
+Some examples can be found by browsing in the repository to /res/msu/albertel/test/ext\_examples.html.
+The \&EXT() function can be used to obtain values for the same parameters as are retrived by some of the other (newer) helper functions
+summarized in the table above, such as \&firstname() which is equivalent to \&EXT(`environment.firstname'),
+and \¶meter\_setting(\$name,\$partid) is equivalent to \&EXT(`resource.'.\$partid.`.'.\$name).
+In such cases the newer (specialized) functions are preferred to \&EXT() on the basis of ease of use.
+