Hi
(Sorry for miswriting Justin's name in my previous message.)
I finally was able to get a working minimal example (see below).
This modest success bring up a few follow-up questions that I hope that list
members could answer.
1. How to test responder's input, e.g., for non-numeric submission?
Should I use the $submission variable with the initial <script> block?
2. If the test should be done inside R : how to deliver the test results to LC?
I ask this because when I tested the ME below with various inputs that do not
follow the expected format (non-numeric values, missing input, etc.) I got only
one kind of warning 'Unable to understand formula'.
I would like to be able to give a more granular feedback to the students, in
the spirit of the original ME.
Thanks
Itay
<problem>
<script type="loncapa/perl">
$ax = &random(1.0, 10, 0.1); # Coordinates of \vec{a}
$ay = &random(1.0, 10, 0.1);
@avec = ($ax, $ay);
$answer="Chose b such that the scalar product with a is zero.";
</script>
<startouttext />
Consider a vector <m eval="on">\( \vec{a} = $ax\hat{x} + $ay\hat{y} \)</m>'.
Provide a vector <m>\( \vec{b} \)</m>, orthogonal to <m>\( \vec{a} \)</m>.
<br />
<endouttext />
<mathresponse answerdisplay="$answer" cas="R" args="@avec">
<answer>
a <- c(LONCAPALIST[1],LONCAPALIST[2]);
b <- c(RESPONSE[1],RESPONSE[2]) ;
abs(sum(a*b))<0.001
</answer>
<textline readonly="no" size="20" />
</mathresponse>
</problem>
On Sat, 24 Oct 2020, at 13:35, Itay wrote:
> Just,
> Thank you for your reply.
> Following your suggestion I tried to create a minimal example based on the
> template
> Math Response using Computer Algebra System R
> Here, too, I am having difficulties.
> The minimal example is enclosed below.
> Typing the correct answer for vector b (ay, -ax)
> provokes the response
> Unable to understand formula.
>
> Note : the command delegated to R was tested directly with R.
>
> Thank you
> Itay
>
>
> <problem>
>
> <script type="loncapa/perl">
> $ax = &random(1.0, 10, 0.1); # Coordinates of \vec{a}
> $ay = &random(1.0, 10, 0.1);
> @avec = ($ax, $ay);
> $answer="Chose b such that the scalar product with a is zero.";
> </script>
>
>
> <startouttext />
> Consider a vector <m eval="on">\( \vec{a} = $ax\hat{x} + $ay\hat{y} \)</m>'.
> Provide a vector <m>\( \vec{b} \)</m>, orthogonal to <m>\( \vec{a} \)</m>.
> <br />
> <endouttext />
>
> <mathresponse answerdisplay="$answer" cas="R" args="@avec">
> <answer>
> abs(sum(LONCAPALIST * RESPONSE))<0.001
> </answer>
> <textline readonly="no" size="20" />
> </mathresponse>
>
> </problem>
>
>
>
>
> On Fri, 23 Oct 2020, at 23:36, Justin Gray wrote:
>> I'm afraid I do not have an answer to your question, but have you considered
>> coding this problem as a mathresponse problem?
>>
>> Best regards,
>> Justin
>> --
>>
>> *Justin Gray*
>> Senior Lecturer | Department of Mathematics
>> Simon Fraser University | SCK 10531
>> 8888 University Dr., Burnaby, B.C. V5A 1S6
>> Canada
>>
>> Simon Fraser University is located on the Unceded Coast Salish Territories
>> of the xʷməθkʷəy̓əm (Musqueam), Səl̓ílwətaʔ/Selilwitulh (Tsleil-Waututh),
>> Kwikwitlem, and Skwxwú7mesh Úxwumixw (Squamish) Peoples
>>
>>
>> On Fri, Oct 23, 2020 at 1:18 PM Itay <it...@nospammail.net> wrote:
>>> __
>>> Hi
>>>
>>> I am trying to develop a custom response problem in which the student
>>> submission is a vector.
>>> A minimal example is provided below.
>>> Regardless of what I typed in the either of the two input fields I get the
>>> response:
>>> 'This question expects a numeric answer.'
>>>
>>> Please advise what am I doing wrong?
>>>
>>> Thanks in advance.
>>> Itay
>>>
>>>
>>> <problem> <!-- begin minimal -->
>>> <script type="loncapa/perl">
>>> $ax = &random(1.0, 10, 0.1); # Coordinates of \vec{a}
>>> $ay = &random(1.0, 10, 0.1);
>>> </script>
>>>
>>> <startouttext />
>>> Consider a vector <m eval="on">\( \vec{a} = $ax\hat{x} + $ay\hat{y}
>>> \)</m>'.
>>> Provide a vector <m>\( \vec{b} \)</m>, orthogonal to <m>\( \vec{a} \)</m>.
>>> <br />
>>> <endouttext />
>>>
>>> <customresponse id="dotProd">
>>> <answer type="loncapa/perl">
>>> for ($i=0; $i<2; $i++) { # Test input sanity.
>>> if ($submission[i] =~ /^\d+\s+\w+$/) { return 'UNIT_NOTNEEDED'; }
>>> if ($submission[i] !~ /^[\d\.]+$/) { return 'WANTED_NUMERIC'; }
>>> }
>>>
>>> # Is submission correct?
>>> $dotProd = $ax * $submission[0] + $ay * $submission[1];
>>> if (abs($dotProd) < 1.0e-3) { return 'APPROX_ANS'; } # Can't expect
>>> EXACT_ANS.
>>> return 'INCORRECT';
>>> </answer>
>>>
>>> <startouttext /><m>\( b_x = \)</m><endouttext />
>>> <textline size="10" readonly="no" spellcheck="none" />
>>> <startouttext /><br /><endouttext />
>>>
>>> <startouttext /><m>\( b_y = \)</m><endouttext />
>>> <textline size="10" readonly="no" spellcheck="none" />
>>> <startouttext /><br /><endouttext />
>>> </customresponse>
>>> </problem> <!-- end minimal -->
>>>
>>>
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