GraphTool
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Graph Tool
This example shows how to get student input in the form of a graph (a circle) by using interactive graphing tools.
PG problem file | Explanation |
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DOCUMENT(); loadMacros( "PGstandard.pl", "MathObjects.pl", "PGML.pl", "parserGraphTool.pl" ); TEXT(beginproblem()); |
Initialization: It is important to include the parseGraphTool.pl macro. |
$h = non_zero_random(-5, 5); $k = non_zero_random(-5, 5); $r = random(1, 4); Context()->variables->add("y" => "Real"); $circle_eq_lhs = Formula("(x-$h)^2 + (y-$k)^2")->reduce; # This grader allows the student to graph the correct circle multiple times. The idea is that # the graph is graded based on appearance. No matter how many times the student graphs the # correct circle, the resulting graph appears the same. $gt = GraphTool("{circle, solid, ($h, $k), ($h + $r, $k)}")->with( bBox => [-11, 11, 11, -11], cmpOptions => { list_checker => sub { my ($correct, $student, $ans, $value) = @_; return 0 if $ans->{isPreview}; my $score = 0; my @errors; my $count = 1; # Get the center and point that define the correct circle and compute the square of # the radius. my ($cx, $cy) = $correct->[0]->extract(3)->value; my ($px, $py) = $correct->[0]->extract(4)->value; my $r_squared = ($cx - $px) ** 2 + ($cy - $py) ** 2; my $pointOnCircle = sub { my $point = shift; my ($x, $y) = $point->value; return ($x - $cx) ** 2 + ($y - $cy) ** 2 == $r_squared; }; for (@$student) { my $nth = Value::List->NameForNumber($count++); $score += 1, next if ($_->extract(1) eq $correct->[0]->extract(1) && $_->extract(2) eq $correct->[0]->extract(2) && $_->extract(3) == $correct->[0]->extract(3) && $pointOnCircle->($_->extract(4))); push(@errors, "The $nth object graphed is not a " . $correct->[0]->extract(1)), next if ($_->extract(1) ne $correct->[0]->extract(1)); push(@errors, "The $nth object graphed should be a " . $correct->[0]->extract(2) . " circle."), next if ($_->extract(2) ne $correct->[0]->extract(2)); push(@errors, "The $nth object graphed is incorrect."); } return ($score, @errors); } } ); |
Setup: Notes: on using this and related Contexts. |
BEGIN_PGML [@ image(insertGraph($graph_image), width => 300, tex_size => 1000) @]* END_PGML |
Main Text: This is how to insert the tikz image. Note the width and tex_size parameters can change the size of the image on the web and as hardcopy. |
ENDDOCUMENT(); |
This doesn't have a question, so we aren't checking an answer. |