Hi Carl,

Thank you for sending that. As it turns out, in this particular problem the 
answers are integers and a tolerance of zero works, but I will definitely keep 
that in mind in the future.

BR,

Gene L. Harding, PE
Associate Professor of ECET
574-520-4190
Purdue University-South Bend

From: lon-capa-users-boun...@mail.lon-capa.org 
[mailto:lon-capa-users-boun...@mail.lon-capa.org] On Behalf Of Carl Lira
Sent: Tuesday, January 24, 2017 8:16 PM
To: 'Discussion list for LON-CAPA users' <lon-capa-users@mail.lon-capa.org>
Subject: Re: [LON-CAPA-users] Unordered Response Question Error

I don't see the script, but you need to have a tolerance. When the value is not 
specified, it defaults to an absolute tolerance of zero. If a floating point 
calculation is done, it will never be exactly an integer. From the author 
manual:

A tolerance parameter determines how closely the system will require the 
student's
answer to be in order to count it correct. The tolerance will default to zero 
if it is not
defined. The tolerance parameter should always be defined for a numerical 
problem
unless you are certain only integer answers are generated from your script and 
you
want students to reply with exactly that integer.
If the computer answer is a floating point number, the tolerance should not be 
zero.
Computers can only approximate computations involving real numbers. For 
instance,
a computer's [decimal] answer to the simple problem 1
3 is "0.33333333333333331". It
should be an infinite series of 3's, and there certainly shouldn't be a "1" in 
the an-
swer, but no computer can represent an infinitely long, infinitely detailed 
real number.
Therefore, for any problem where the answer is not an integer, you need to 
allow a
tolerance factor, or the students will find it nearly impossible to exactly 
match the
computer's idea of the answer. You may find the default tolerance too large for 
some
problems, so adjust as appropriate.


Hm, I think that last line should say "if you use the colorful editor tolerance 
template, the default tolerance may be too large...". I think the template 
defaults to 5%.

the format affects the display, not the calculations.

From: 
lon-capa-users-boun...@mail.lon-capa.org<mailto:lon-capa-users-boun...@mail.lon-capa.org>
 [mailto:lon-capa-users-boun...@mail.lon-capa.org] On Behalf Of Harding, Gene L
Sent: Tuesday, January 24, 2017 8:23 AM
To: Discussion list for LON-CAPA users 
<lon-capa-users@mail.lon-capa.org<mailto:lon-capa-users@mail.lon-capa.org>>
Subject: Re: [LON-CAPA-users] Unordered Response Question Error

Hi Carl,

The ! was commenting out the parameter, something I tried among several 
permutations of syntax hoping to get something to work. The error message is 
the same whether it is there or commented out. I originally also had a sig figs 
param in it, but deleted it. I think that eliminated one error.

I have tried putting the unit= and format= in the answer and value fields, but 
no luck there, either.

Gene L. Harding, PE
Associate Professor of ECET
574-520-4190
Purdue University-South Bend

From: 
lon-capa-users-boun...@mail.lon-capa.org<mailto:lon-capa-users-boun...@mail.lon-capa.org>
 [mailto:lon-capa-users-boun...@mail.lon-capa.org] On Behalf Of Carl Lira
Sent: Monday, January 23, 2017 11:22 PM
To: 'Discussion list for LON-CAPA users' 
<lon-capa-users@mail.lon-capa.org<mailto:lon-capa-users@mail.lon-capa.org>>
Subject: Re: [LON-CAPA-users] Unordered Response Question Error

not sure of the impact of the ! in the responseparam field. I believe you 
should have some tolerance if you have a calculated real number, e.g.

<responseparam name="tol" type="tolerance" default="2%" description="Numerical 
Tolerance" />




From: 
lon-capa-users-boun...@mail.lon-capa.org<mailto:lon-capa-users-boun...@mail.lon-capa.org>
 [mailto:lon-capa-users-boun...@mail.lon-capa.org] On Behalf Of Harding, Gene L
Sent: Monday, January 23, 2017 10:00 PM
To: 'lon-capa-users@mail.lon-capa.org' 
<lon-capa-users@mail.lon-capa.org<mailto:lon-capa-users@mail.lon-capa.org>>
Subject: [LON-CAPA-users] Unordered Response Question Error

Hi,

I am trying to embed some unordered numericalresponse parameters inside an xml 
table. I modeled my xml after the example in LON-CAPA, but am having two 
problems with it. The first problem is an error referring to tolerance range, 
and the second is incompatible units. This is a screenshot:
[cid:image001.jpg@01D276E4.733722E0]

This is the code I am using:
<startouttext />
A $Pa dBm, $fa-MHz RF input signal and a $Pb dBm, $fb-MHz LO signal are applied 
to a nonlinear mixer with $Zin-&Omega; impedance. Complete the table of IF 
cross products for m,n equal 1,2.

<! Display numeric response inside a table >
<table style="width:400px" border="1" cellpadding="1" >
  <tr>
    <td> m </td>  <td> n </td>  <td> |mf<sub>a</sub> &plusmn; nf<sub>b</sub>| 
</td>  <td> Cross Products </td>
  </tr>
  <tr>
    <td>1</td>  <td>1</td>
    <td>
<numericalresponse format="0f" unit="MHz" id="11">
    <answergroup type="ordered">
        <answer type="unordered">
            <value>$fa</value>
            <value>$fb</value>
        </answer>
    </answergroup>
    <!responseparam name="tol" type="tolerance" default="0" 
description="Numerical Tolerance" />
    <textline size="8" readonly="no" />
    <textline size="8" readonly="no" />
</numericalresponse>
    </td>  <td>$f11_1 MHz $f11_2 MHz</td>
  </tr>
  <tr>
    <td>1</td>  <td>2</td>
  </tr>
  <tr>
    <td>2</td>  <td>1</td>
  </tr>
  <tr>
    <td>2</td>  <td>2</td>
  </tr>
</table>

<endouttext />

Any ideas why I am getting these two errors?

Thanks for any advice you can provide.

Best regards,

Gene L. Harding, PE
Associate Professor of ECET
574-520-4190
Purdue University-South Bend

_______________________________________________
LON-CAPA-users mailing list
LON-CAPA-users@mail.lon-capa.org
http://mail.lon-capa.org/mailman/listinfo/lon-capa-users

Reply via email to