Sage Embedding

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Using the Sage Cell Server


This PG code shows how to embed a call to the Sage Cell Server from within a problem.

  • Download file: File:Axb span.txt (Change the file extension from .txt to .pg when you save it. You also need to replace every occurrence of 'REPLACE_WITH_SCRIPT' with '<script' in order for the .pg file to work.)



Problem Techniques Index

PG problem file Explanation
  loadMacros("PGstandard.pl",
             "MathObjects.pl",
             "sage.pl",
  );

The sage.pl macro is not yet part of the standard WeBWorK distribution. You will need to download the macro file from above and place it in your local macros directory for this to work.

###########################################################
##
##  pg initializations and regular WeBWorK code

$a = random(2,5,1);

The WeBWorK set up for the problem is the same, but in addition you have to consider how you will pass the problem parameters into Sage. For example, if you want to pass $f = (x-(-2))(x+2)(x+4) it may be best to create two versions of f: $f_raw = (x-(-2))*(x+2)*(x+4); to pass to Sage and the math object $f = Compute("$f_raw"); to use in WeBWorK.


$SageCode = <<SAGE_CODE;

SageAnswer = integrate(sin($a*x),x,0,pi)
print SageAnswer

$SageCode = <<SAGE_CODE;

denotes the beginning of the Sage Python code to be inserted into the WeBWorK problem. This will be paired at the end with and ending SAGE_CODE which must be left-justified. This portion will create a perl variable $SageCode which is the complete Python text.

In this example, you will also desire that the value of SageAnswer be sent back to the WeBWorK problem for further use (such as answer checking).


~~@interact
def _(x1=slider(-3,3,1/20,1), x2=slider(-3,3,1/20,1)): 
     
    G = arrow((0,0),x1*At[0],rgbcolor=(0,0,1)) 
    G += arrow(x1*At[0],x1*At[0]+x2*At[1],rgbcolor=(0,1,0)) 
    G += arrow((0,0),($b1,$b2),rgbcolor=(1,0,0),width=5) 
    G += text("A1",(x1*At[0][0]/2,x1*At[0][1]/2),fontsize=30,color='purple')
    G += text("A2",(x1*At[0][0]+x2*At[1][0]/2,x1*At[0][1]+x2*At[1][1]/2),
        fontsize=30,color='purple')
    G += text("b",($b1/2,$b2/2),fontsize=40,color='purple')
    G += point(x1*At[0],color='blue',pointsize=40)
    G += point(($b1,$b2),color='red',pointsize=30)
    G += point(x1*At[0]+x2*At[1],color='green',pointsize=40)
    G += point(($b1,$b2),color='red',pointsize=20)
#  Add fixed originals and dashed modified version of these
    show(G,frame=False)

Main sage script:

Working Sage code will work verbatim except for a couple of notational changes caused by conflicting syntax between perl and sage. In particular, since "@" is used for tables in perl and for interacts in sage, one will need to replace "@" with "~~@". Further, WeBWorK uses \( and \) to delimit latex and "$" for variables while Sage uses "$' to delimit latex. Therefore, changing each of Sage's latex delimiters to the \( and \) format averts any conflict.


    html('<input type=hidden size=15 name="\{ANS_NUM_TO_NAME(1)\}" 
        id="\{ANS_NUM_TO_NAME(1)\}" value="%s">' %str(x1) )
    html('<input type=hidden size=15 name="\{ANS_NUM_TO_NAME(2)\}"
        id="\{ANS_NUM_TO_NAME(2)\}" value="%s">' %str(x2) )
</script>
</div>

Hidden answer boxes written by the Sage Cell Server

At the end of Sage code (usually an interact) you need to manually pass the answers you want from Sage back into WeBWorK by using Sage to write the answer <input> boxes (hidden since the student doesn't need to see them). Using \{ANS_NUM_TO_NAME()\} ensures they are given the correct names by WeBWorK.

###########################################################
##
## single cell server script
##
## script that sends the Sage code above to the
## single cell server and writes the return into
## the webpage
##

TEXT(MODES(TeX=>"", HTML=><<'SAGE_SCRIPT'));

<script src="http://aleph.sagemath.org/static/jquery.min.js"></script>
<script src="http://aleph.sagemath.org/embedded_sagecell.js"></script>

<script>
$(function () {
  sagecell.makeSagecell({inputLocation:  '#sagecell',
                         template:       sagecell.templates.minimal,
                         autoeval:        true, 
                         evalButtonText: 'Reset the interactive display'});
});
</script>

SAGE_SCRIPT

This section writes the javascript into the webpage that feeds the correct <div> to the Sage Cell Server and writes the output into the question page.

####################################################
##
## Lower WeBWorK text
##
## Problem display following the Sage cell
##

Context()->texStrings;

BEGIN_TEXT
When you are comfortable with the coefficients that
you have chosen, press the submit button below.
END_TEXT

Context()->normalStrings;

#######################
# Answer Evaluation

$showPartialCorrectAnswers = 1;

ANS( $x1ans->cmp() );
ANS( $x2ans->cmp() );

Answer Evaluation:

The answers are checked in the same order as the input boxes appear in the Sage section. Some tweaking may be required to get the Sage format agreeing with the WeBWorK format of the objects the evaluator is checking

###########################################################
##
## Hint(s), delete or comment if not used
##

Context()->texStrings;

$showHint = 2;
BEGIN_HINT
By adjusting the sliders, you are changing the length of the
corresponding vector.  Remember that a negative coefficient
makes the vector point in the opposite direction.
END_HINT

$showHint = 4;
$x1low = $x1-1/3;
$x1high = $x1+1/5;
BEGIN_HINT
Consider choosing a value for the first coefficient somewhere
between $x1low and $x1high.
END_HINT

Context()->normalStrings;

###########################################################
##
## Solution, delete or comment if not used
##

Context()->texStrings;

BEGIN_SOLUTION

Notice that \(($x1) *A_1 + ($x2) *A_2 = $b\) 
END_SOLUTION

Context()->normalStrings;

ENDDOCUMENT(); # This should be the last executable line in the problem.

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