[LON-CAPA-users] Understanding formularesponses

[Peter Riegler]

Hi,

I agree with Justin that sampling is the easiest (and most efficient) 
approach. Using maxima you would have to use mathresponse with a program 
code like
tol:0.001;
is(RESPONSE[1]=log(2)) or is( abs(RESPONSE[1]-log(2)) <= tol);

Logically all boils down to the 2nd "is" statement, which is exactly 
what formula response w/ sampling does.

Peter

Justin Gray wrote:

> Hi Ray,
> 
> If you want to allow a numerical approximation to log(2) as a correct 
> answer, then I recommend that you use point sampling rather than a 
> computer algebra system to evaluate the answer. Try this:
> 
> <problem>
> <part><startouttext />Numerical Tolerance works well with formula 
> response when point sampling is used. Either log(2) or 0.6931 are graded 
> correct:<endouttext />
> 
> <formularesponse answer="log(2)" samples="x@1:5#4">
>     <responseparam description="Numerical Tolerance" type="tolerance" 
> default="0.0001" name="tol" />
>     <textline size="25" readonly="no" />
>    
> </formularesponse>
> </part>
> 
> <part><startouttext />Numerical Tolerance does not seem to work well 
> with formula response when the expression is evaluated in Maxima. This 
> time log(2) is correct but 0.6931 is graded as incorrect:<endouttext />
> <formularesponse answer="log(2)">
>     <responseparam description="Numerical Tolerance" type="tolerance" 
> default="0.0001" name="tol" />
>     <textline size="25" readonly="no" />
>    
> </formularesponse>
> </part>
> </problem>
> 
> Justin
> 
> 
> On Sun, Sep 7, 2008 at 11:36 PM, Ray Batchelor <batchelo@sfu.ca 
> <mailto:batchelo@sfu.ca>> wrote:
> 
> 
>     How would you create a formula response question for which you want both
>     "log(2)" to be the answer both symbolically and numerically?
> 
>     -- 
>     Ray
> 
> 
> 
> 
> -- 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Justin Gray                                                  
> Dept. of Mathematics                                  
> Simon Fraser University
> 8888 University Drive
> Burnaby, B.C. V5A 1S6
> Canada
> Tel. +1 778-782-4237
> Fax. +1 778-782-4947
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
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> <http://www.terryfoxrun.org/ENRunner/default.asp?s=1&RunnerID=56229>
> 
> 
> 

-- 
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