[LON-CAPA-users] Duplicated ids found (SOLVED!)

Itay Furman itayf at nospammail.net
Wed Oct 30 23:33:47 EDT 2013


Hi,

As suggested by Raymond I manually change the id in the imported 
library file, and that solved the problem.

In my original problem file I did not include id attribute for the 
import tag.  The id="11" was added automatically during publication.
Although the automatic addition of id attributes is documented, I 
missed that point until the error hit me.

Thank again,
Itay


On Sun, 27 Oct 2013, Itay Furman wrote:

> Date: Sun, 27 Oct 2013 22:46:34 +0200 (IST)
> From: Itay Furman <itayf at nospammail.net>
> To: Discussion list for LON-CAPA users <lon-capa-users at mail.lon-capa.org>
> Subject: Re: [LON-CAPA-users] Duplicated ids found
> 
> On Sun, 27 Oct 2013, Raymond Batchelor wrote:
>
>> It seems to me that the id="11" is used within the imported file (which 
>> imports yet another library file) and redundantly in the actual problem 
>> file to import the first library file.  I think you 'might' want to use an 
>> id other than "11" in your problem file, for the import.
>
> I see.
> I will make the changes and test them later, when the questions will not be 
> in active use.
>
> Thanks,
> Itay
>
>> 
>> ----- Original Message -----
>> From: "Itay Furman" <itayf at nospammail.net>
>> To: lon-capa-users at mail.lon-capa.org
>> Sent: Sunday, 27 October, 2013 08:45:18
>> Subject: [LON-CAPA-users] Duplicated ids found
>> 
>> Hi,
>> 
>> This is problem a newbie question. But I didn't find information on
>> this. Sorry for that.
>> 
>> After publishing a problem I get the following error message:
>> 
>> [start]
>> ERROR: Duplicated ids found, problem will operate incorrectly.
>> Duplicated ids seen:
>> 11
>> This error occurred while processing response 12 in part
>> [end]
>> 
>> I could find in my code only a single id="11".
>> Note that the numerical ids in
>>   <import id="11">/res/jce/itayf/pub/lib/const_phys.library</import>
>> and
>>   <numericalresponse unit="C" format="2E" answer="$q" id="12">
>> were added by lon-capa after publication.
>> 
>> The code follows below.
>> 
>> Thanks in advance,
>> Itay
>> 
>> [start code]
>> <problem>
>>   <comment>
>>     File    = elec_coulomb_identical-hanging-charges.problem
>>     Author  = Itay Furman, PhD, itayf at fastmail.fm
>>     Created = 2013-10-08
>>     Updated = 2013-10-08
>>     Version = 0.01
>>
>>     Source  = Expanded from a problem by Michael Friedberg, JCE.
>>   </comment>
>>
>>   <import id="11">/res/jce/itayf/pub/lib/const_phys.library</import>
>>
>>   <script type="loncapa/perl">
>>     # Set-up
>>
>>     $k_coulomb = $Coulomb_Const;
>>     $g      = 9.8;                                # Gravity acceleration [m 
>> / s^2].
>>     $len    = &random(10, 50, 5);		  # String length [cm].
>>     $theta  = &random(4,25,1);                    # Angle between string 
>> and vertical [degrees].
>>     $th_rad = $theta* $Pi / 180;                  # Same angle [rad].
>>     $mass   = &random(5,80,5);                    # Body mass [g].
>>
>>     # Compute the magnitude of the charge on each body.
>>     $q = 2 * ($len/100) * sin($th_rad) * sqrt(($mass/1000) * $g * 
>> tan($th_rad) / $k_coulomb);
>>     # Note the following factors are required:
>>     # 1/100   in ($len/100)       to convert        $len: [cm]  -> [m].
>>     # 1/1000  in ($mass/1000)     to convert       $mass: [g]   -> [kg].
>>     # $Pi/180 in ($theta*$Pi/180) to convert sin()'s arg: [deg] -> [Rad].
>>   </script>
>>
>>   <startouttext />
>>   <h2>The Electrostatic Force Between a Pair of Identical Hanging Point 
>> Charges</h2>
>>
>>   <p>
>>     Two point bodies, each having a mass of <num>$mass</num> [g], are 
>> connected to identical massless
>>     isolating strings whose length is <num>$len</num> [cm].
>>     The strings are connected to the same hook on the ceiling.
>>   </p>
>>   <p>
>>     The bodies carry identical charges.
>>     Therefore, due to electrostatic repulsion, each string is inclined with 
>> an angle of
>>     $theta<sup>o</sup> relative to the line that pass through the hook and 
>> is orthogonal to the
>>     ceiling.
>>   </p>
>>   <endouttext />
>>
>>   <part id="q" display="Compute the charge.">
>>     <startouttext />
>>     <strong>Compute: </strong> the electric charge on each body is
>>     <endouttext />
>>
>>     <numericalresponse unit="C" format="2E" answer="$q" id="12">
>>       <responseparam name="tol" type="tolerance" default="2%" 
>> description="Numerical Tolerance" />
>>       <textline readonly="no" />
>>     </numericalresponse>
>>   </part>
>>
>>   <img alt="A pair of identical hanging charged masses."
>> src="/res/jce/itayf/pub/share/img/131012_pair-hanging-charges.jpg"
>> encrypturl="no" />
>> <allow
>> src="/res/jce/itayf/pub/share/img/131012_pair-hanging-charges.jpg" />
>> </problem>
>> 
>> [end code]
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>> 
>> 
>


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