[LON-CAPA-users] How to realize a randomly generated downloadable data set?

[Gerd Kortemeyer]

On May 7, 2007, at 2:56 PM, Gerd Kortemeyer wrote:

>
> Would the students web-savvy enough to copy the data out of a  
> textarea?

If yes, then the problem below might do the trick. Alternatively, one  
could put a piece of JavaScript around the data which provides a "file."


> On May 7, 2007, at 2:45 PM, Peter Riegler wrote:
>>
>>
>> I want my students to do a frequency analysis of a noisy  
>> monofrequential signal (by FFT or whatever). What I have in mind  
>> is to have a problem where the student is offered a downloadable  
>> file together with a single numerical answer field for entering  
>> the obtained signal frequency.
>>
>> If I had a static data file I would make a published resource out  
>> of it and hardlink it into the problem file. However, I would like  
>> to have individual, i.e. random, data files for each student. Is  
>> there a way of having dynamic data files as resources?
>>

<problem>
<script type="loncapa/perl">$omega=2*$pi/&random(30,60,1);
$phi=&random(1,2,0.1);
$amp=&random(3,10,1);
for ($t=0;$t<=600;$t++) {
      $func=$amp*(sin($omega*$t+$phi)+&random(-0.2,0.2,0.01));
      $data.="$t,$func\n";
}</script>
<startouttext />Copy the data below and perform a Fourier  
analysis.<br />
<textarea cols="20" rows="10">$data</textarea><br />
What is the angular frequency of the data?<endouttext />
<numericalresponse unit="rad/s" format="3s" answer="$omega">
	<responseparam type="tolerance" default="5%" name="tol"  
description="Numerical Tolerance" />
	
	<textline readonly="no" />
	
</numericalresponse>
</problem>