Graph Tool, plotting a line

Interactive graphing tool problem that asks the student to plot a circle.

Complete Code

POD for Macro Files

parserGraphTool.pl

PG problem file

Explanation

DOCUMENT();

loadMacros('PGstandard.pl', 'PGML.pl', 'parserGraphTool.pl',
  'PGcourse.pl');

Preamble

This example shows how to get student input in the form of a graph (a circle) by using interactive graphing tools. Load the parserGraphTool.pl macro for this.

#  * availableTools: this determines which tools should be shown on the

$x0 = non_zero_random(-6,6);
$y0 = non_zero_random(-6,6);
$line = nicestring([$y0,$x0],['x','y']);


$gt = GraphTool("{line, solid, ($x0, 0), (0, $y0)}")->with(
    bBox           => [ -11, 11, 11, -11 ],
    availableTools =>
        [ 'PointTool', 'LineTool', 'CircleTool', 'QuadraticTool', 'CubicTool', 'FillTool', 'SolidDashTool' ],
);

Setup

A cubic is created with 3 random zeros and a random y-intercept.

The GraphTool method creates the graph tool object. The only argument is the correct answer. This is a string that contains a list of objects that the student will be expected to graph. Each object is a brace delimited list of the attributes of the object. The first attribute in each list is the type of object to be graphed, cubic in this case. What the remaining attributes are depend on the type. For a cubic the second attribute is whether the object is to be solid or dashed, the remaining arguments are the 4 points of the cubic.

The ->with method is then used to set options for the GraphTool object. In this case the options that are set are:

bbox: this is an array reference of four values xmin, ymax, xmax, ymin indicating the upper left and lower right corners of the visible graph. graph tool.

There is a default checker for the GraphTool that will mark correct a student answer that ‘looks’ like the correct one. For simple graphs, the default should be sufficient. If not see XXXX for an example with a custom answer checker.

BEGIN_PGML
On the graph below, plot the line [`[$line] = [$x0*$y0]`]

[_]{$gt}

END_PGML

Statement.

The code [_]{$gt} inserts the GraphTool.

BEGIN_PGML_SOLUTION
Two points are needed off this line.  It could be put in slope-intercept form
which would give a [`y`]-intercept and then a second point could be determined
from the slope.

Alternatively, the intercept form on the line is found by dividing the equation
by the right hand side to
[```\frac{x}{[$x0]}+ \frac{y}{[$y0]}=1```]
and thus the [`x`]-intercept is number in the fraction under the [`x`] or
 [$x0] and the [`y`]-intercept is the number in the fraction under the [`y`]
 or [$y0].  The solution is

[@ $gt->generateAnswerGraph @]*

END_PGML_SOLUTION


ENDDOCUMENT();

Solution

A solution should be provided here.