<div dir="ltr">Hi Josh,<div><br></div><div>The easy solution is to move this calculation to the <part> that requires it. You are allowed multiple <script> blocks inside a problem. So you can split up the single <script> block that occurs at the top of your problem into several different <script> blocks belonging to each <part>. </div>
<div><br></div><div>Then, since you use "Show Parts One-at-a-Time" the <script> of each part shouldn't be evaluated until the &submission() values from the previous <part> have been entered.</div>
<div><br></div><div>Todd</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Sep 2, 2013 at 1:03 PM, Josh Wolosz <span dir="ltr"><<a href="mailto:jwolosz@slrsd.org" target="_blank">jwolosz@slrsd.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div><div><div><div><div>Hi Everyone,<br><br>I have a question in regards to Custom Response problems. I
would like to try moving some of my labs into lon-capa, and one of the
first ones involves working with percent error (for high school freshman).<br>
<br></div>Here's what I would like to have happen:<br><br></div>1) Students enter an estimated value<br></div>2) Students enter the actual/measured value<br></div>3) Students then input their percent error which loncapa calculates and determines if they are correct or not<br>
<br></div>Here is the script I have tried:<br><br><b><script type="loncapa/perl"><br># Get the entered answer. First argument is partID, second is responseID<br>$given=&submission(1,11);<br>$example='You chose '.$given.' m';<br>
$given2=&submission(3,4);<br>$example2='You chose '.$given2.' m';<br>$a=&abs($given2-$given)/$given2;<br></script></b><br><br></div>I'm getting an error returned saying there is an illegal division by zero, specifically:<br>
<br><b>$a=&abs($given2-$given)/$given2;<br><br></b></div>I
understand that at the beginning of the problem nothing has been
submitted, so $given2 has no value. Is there a way around this?
Thanks for your help, and I apologize if it is a very simple solution
that I am missing.<br>
<br></div><div>Sincerely<br></div><div>Joshua Wolosz<br><br></div><div>The full code is:<br><br><problem><br><br> <parameter name="ordered" id="13" type="string_yesno" default="no" description="Show Parts One-at-a-Time" /><br>
<br><script type="loncapa/perl"><br># Get the entered answer. First argument is partID, second is responseID<br>$given=&submission(1,11);<br>$example='You chose '.$given.' m';<br>$given2=&submission(3,4);<br>
$example2='You chose '.$given2.' m';<br></div><div>$a1=100*&abs($given2-$given)/$given2;<br></div></script><br><br><part id="1"><br><startouttext /><br><i><b>Note:</b>
You do not need to include the units when you input your
calculations.</i><br></br><br>
<br>What did you estimate the width of the object to be?<br><endouttext /><br><customresponse answerdisplay="$example" id="11"><br> <answer type="loncapa/perl"># We do not want a vector<br>
if ($submission=~/\,/) { return 'EXTRA_ANSWER'; }<br># No units needed<br>if ($submission=~/^\d+\s+\w+$/) { return 'UNIT_NOTNEEDED'; }<br># Need a numerical answer here<br>if ($submission!~/^[\d\.]+$/) { return 'WANTED_NUMERIC'; }<br>
{ return 'EXACT_ANS'; }</answer><br> <textline readonly="no" /><br></customresponse><startouttext />meters<endouttext /><br></part><br><br><part id="3"><br>
<startouttext /><br>What did you <u>measure</u> the width of the object to be? <br><endouttext /><br><customresponse answerdisplay="$example2" id="4"><br> <answer type="loncapa/perl"># We do not want a vector<br>
if ($submission=~/\,/) { return 'EXTRA_ANSWER'; }<br># No units needed<br>if ($submission=~/^\d+\s+\w+$/) { return 'UNIT_NOTNEEDED'; }<br># Need a numerical answer here<br>if ($submission!~/^[\d\.]+$/) { return 'WANTED_NUMERIC'; }<br>
{ return 'EXACT_ANS'; }</answer><br> <textline readonly="no" /><br></customresponse><startouttext />meters<endouttext /><br></part><br><br><part id="5"><br>
<startouttext /><br>What was your percent error for the width?<br><endouttext /><br><numericalresponse answer="$a1" id="194"><br><responseparam name="tol" type="tolerance" default="0.5%" description="Numerical Tolerance" /><br>
<textline readonly="no" /><br></numericalresponse><br></part><br></problem</div>
<br>
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