<b>Matrix.</b> (name: <span class="tt">matrix</span>)<br>
As for vector answer
, each coefficient is evaluated and compared to the
corresponding coefficient of the correct answer.
<p>
Three option words are available:
<span class="tt wims_code_words">split_coeff</span>,
<span class="tt wims_code_words">split_row</span>,
<span class="tt wims_code_words">split_column</span>.
The answer is partially correct if a percentage (50 %) of correct coefficients
or rows or columns is correct.
</p><p>
If <span class="tt wims_code_words">n</span> is the number of the question,
the variables <span class="tt wims_code_words">result</span>n contains
a matrix with 1 and 0 according to the position of the correct and wrong
coefficients (or 0.5 if the precision is not sufficient).
</p>