[LON-CAPA-dev] How does formularesponse work

Peter Riegler lon-capa-dev@mail.lon-capa.org
Wed, 23 May 2007 10:32:18 +0200


Hi Guy,

argh, shame on me!

Thanks!

Peter

PS: Funny though that wrong responses are graded as correctly ...

Guy Albertelli II wrote:

> Hi Peter,
> 
> Looks like a typo.
> 
> 
>>we have a problem using formula response here, which brings up the 
>>question how it works internally. Unfortunately, I am not really capable 
>>of understanding what is going on in caparesponse.pm.
>>
>>So far, my idea of formularesponse has been that it runs nested 
>>for-loops w.r.t. the sampling variables. For instance,
>>
>><formularesponse samples="x,y@-3,-3,;2,2#4" answer="$answer" id="11">
>>
>>should result in something like
>>
>>for each x value
>>    for each y value
>>        check whether $answer evaluated at x and y equals
>>		response evaluated at x an y
>>        if not break out of the for loops and return false
>>    end
>>end
> 
> 
> Yes, it should, however you have a ; where you want a :
> 
> x,y@-3,-3,;2,2#4
> 
> Will sample at x=-3,y=-3, and x=2,y=2
> 
> x,y@-3,-3:2,2#4
> 
> Will sample at 4 random points in the box defined by -3 <= x <= 2, and
> -3 <= y <= 2
> 
> 
>><formularesponse samples="x,z,t,C@-3,-3,-3,-3;2,2,2,2#4" 
>>answer="$integral" id="11">
> 
> 
> and similarly here there is a ; where you likely want a :

-- 
Peter Riegler
Fachhochschule Braunschweig/Wolfenbüttel
Salzdahlumer Str. 46/48, 38302 Wolfenbüttel
Tel. +49 5331 939 6314, Fax. +49 5331 939 6002
email: p.riegler@fh-wolfenbuettel.de
http://public.rz.fh-wolfenbuettel.de/~riegler