MatrixCustomAnswerChecker1

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Matrices and Custom Answer Checkers

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This PG code shows how to use a multianswer answer checker to evaluate an open-ended question about matrices.

• File location in OPL: FortLewis/Authoring/Templates/LinAlg/MatrixCustomAnswerChecker1.pg
• PGML location in OPL: FortLewis/Authoring/Templates/LinAlg/MatrixCustomAnswerChecker1_PGML.pg

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PG problem file	Explanation
Problem tagging data	Problem tagging:
DOCUMENT(); loadMacros( "PGstandard.pl", "MathObjects.pl", "parserMultiAnswer.pl", "AnswerFormatHelp.pl", "PGcourse.pl", ); $showPartialCorrectAnswers = 0; TEXT(beginproblem());	Initialization:
Context('Matrix'); $A = Matrix([[1,1],[0,1]]); $B = Matrix([[1,0],[1,1]]); $multians = MultiAnswer($A, $B)->with( singleResult => 1, checker => sub { my ( $correct, $student, $answerHash ) = @_; my @s = @{$student}; $s0 = Matrix($s[0]); $s1 = Matrix($s[1]); return $s0 * $s1 != $s1 * $s0; } );	Setup: Construct two matrices $A and $B that do not commute and therefore serve as a correct answer. Use a $multians object with a custom answer checker subroutine. The answer checker uses my ( $correct, $student, $answerHash ) = @_; to grab the inputs (the correct answer, the student answer, and the answer hash table info). Then, put the student's two answers into an array @s using my @s = @{$student};. Make sure the student's first matrix $s[0] is converted to a MathObject matrix $s0 using $s0 = Matrix($s[0]); and similarly for the student's second matrix. The return value, which is boolean, is the truth value of the statement $s0 * $s1 != $s1 * $s0.
Context()->texStrings; BEGIN_TEXT Give an example of two \( 2 \times 2 \) matrices \( A \) and \( B \) such that \( AB \ne BA \). $BR $BR \( A = \) \{ $multians->ans_array(5) \} $BR $BR \( B = \) \{ $multians->ans_array(5) \} END_TEXT Context()->normalStrings;	Main Text: Make sure that both answer arrays are called as methods on the $multians object (i.e., $multians->ans_array(5) should be called for each answer array. Note that ans_array(w) produces an answer array of boxes each w characters wide.
install_problem_grader(~~&std_problem_grader); ANS( $multians->cmp() ); COMMENT('MathObject version.'); ENDDOCUMENT();	Answer Evaluation:

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