DynamicImages3
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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.
| 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 |
$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"]);
#
# 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
# 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. |
