DynamicImages3

Dynamic Graphic Images, with Filled Regions

This code snippet shows the essential PG code to check student answers that are equations. Note that these are insertions, not a complete PG file. This code will have to be incorporated into the problem file on which you are working.

Problem Techniques Index

PG problem file	Explanation
DOCUMENT(); loadMacros( "PGstandard.pl", "PGgraphmacros.pl", # "PGnumericalmacros.pl", # might be useful ); TEXT(beginproblem());	Initialization: To do ..(what you are doing)........., we don't have to change the tagging and documentation section of the problem file. In the initialization section, we need to include the macros file -------.pl.
$xmin = random(-3,-1,1); $xmax = random(1,3,1); $ymin = random(-3,-1,1); $ymax = random(1,3,1); # # filled triangle with dark border # $gr1 = init_graph(-4,-4,4,4,grid=>[8,8],axes=>[0,0],pixels=>[400,400]); $gr1->new_color("lightgreen",156,215,151); # RGB $gr1->new_color("darkgreen", 0, 86, 34); $gr1->moveTo($xmin,$ymin); $gr1->lineTo($xmax,$ymin,"darkgreen",2); # bottom edge $gr1->lineTo($xmin,$ymax,"darkgreen",2); # hypotenuse $gr1->lineTo($xmin,$ymin,"darkgreen",2); # left edge $gr1->fillRegion([$xmin+0.1,$ymin+0.1,"lightgreen"]); # # Note: we could fill in any polygon by adding more sides # # A filled in circle # $gr3 = init_graph(-5,-5,5,5,grid=>[10,10],axes=>[0,0],pixels=>[400,400]); $gr3->new_color("lightblue", 214,230,244); # RGB $gr3->new_color("darkblue", 100,100,255); add_functions($gr3, " sqrt(4-x^2) for x in <-2,2> using color:darkblue and weight:2", "-sqrt(4-x^2) for x in <-2,2> using color:darkblue and weight:2" ); $gr3->fillRegion([0.1,0.1,"lightblue"]);	Setup: We specify that the Context should be ......, and define the answer to be a formula. # filled rectangle with dark border # uses some macros directly from GD.pm # $gr2 = init_graph(-4,-4,4,4,grid=>[8,8],axes=>[0,0],pixels=>[300,300]); $lightblue = $gr2->im->colorAllocate(148,201,255); $darkblue = $gr2->im->colorAllocate(100,100,255); # # translate from graph coordinates to pixel coordinates # $xminpixel = $gr2->ii($xmin); $xmaxpixel = $gr2->ii($xmax); $yminpixel = $gr2->jj($ymin); $ymaxpixel = $gr2->jj($ymax); # # use filledRectangle and rectangle from GD.pm, accessed via ->im-> # $gr2->im->filledRectangle($xminpixel,$yminpixel,$xmaxpixel,$ymaxpixel,$lightblue); $gr2->im->rectangle($xminpixel,$yminpixel,$xmaxpixel,$ymaxpixel,$darkblue); ################ # Graph # # filled circle with dark border # uses some macros directly from GD.pm # $r = random(1,4,1); # radius $gr3 = init_graph(-5,-5,5,5,grid=>[10,10],axes=>[0,0],pixels=>[400,400]); $gr3->lb('reset'); foreach my $i (1..4) { $gr3->lb( new Label(-4.7,$i,$i,'black','center','middle')); $gr3->lb( new Label(-4.7,-$i,-$i,'black','center','middle')); $gr3->lb( new Label($i,-4.7,$i,'black','center','middle')); $gr3->lb( new Label(-$i,-4.7,-$i,'black','center','middle')); } $gr3->lb( new Label(4.7,0.2,'x','black','center','middle')); $gr3->lb( new Label(0.2,4.7,'y','black','center','middle')); $lightblue = $gr3->im->colorAllocate(148,201,255); $darkblue = $gr3->im->colorAllocate(100,100,255); # # use arc() and fillToBorder() from GD.pm, accessed via ->im-> # $cxpixel = $gr3->ii(0); # x-coordinate of center $cypixel = $gr3->jj(0); # x-coordinate of center $dxpixel = $gr3->ii($r) - $gr3->ii(-$r); # diameter of ellipse, x-direction $dypixel = $gr3->jj($r) - $gr3->jj(-$r); # diameter of ellipse, y-direction # # 0 to 360 are degrees $gr3->im->arc($cxpixel,$cypixel,$dxpixel,$dypixel,0,360,$darkblue); $gr3->im->fillToBorder($cxpixel,$cypixel,$darkblue,$lightblue);
BEGIN_TEXT $BCENTER \{ image( insertGraph($gr1), height=>400, width=>400, tex_size=>800 ) \} $ECENTER $PAR $BCENTER \{ image( insertGraph($gr2), height=>400, width=>400, tex_size=>800 ) \} $ECENTER $PAR $BCENTER \{ image( insertGraph($gr3), height=>400, width=>400, tex_size=>800 ) \} $ECENTER END_TEXT	Main Text: The problem text section of the file is as we'd expect.
$showPartialCorrectAnswers = 1; ENDDOCUMENT();	Answer Evaluation: As is the answer.

Problem Techniques Index