Re: Replacing a part of a list/matrix?
- Subject: [mg2193] Re: Replacing a part of a list/matrix?
- From: ianc (Ian Collier)
- Date: Fri, 13 Oct 1995 06:25:02 GMT
- Approved: usenet@wri.com
- Distribution: local
- Newsgroups: wri.mathgroup
- Organization: Wolfram Research, Inc.
- Sender: daemon at wri.com ( )
In article <45d22j$63m at ralph.vnet.net>, olee at ripco.com (O. Lee) wrote:
> I am trying to assign a value to a matrix position, such as:
>
> pop[[ x,y ]] = value
>
> in a module function. When I try manually assigning a value
> to the matrix position outside of the module, it works. When
> I run the function with the statement, Mathematica gives me
> the following error message:
>
> Part::setps:
>
> {{1, 1, 0, 0}, <<1>>}
> in assignment of part is not a symbol.
>
> Can anyone tell me how to get the assignment statement to
> work! I isolated the problem in the function to this line
> and I am sure that what I just described was the problem.
> I have tried using the command:
>
> pop=ReplacePart[pop,value,{x,y}]
>
> but it gives me even more error messages! Help me please!
> I appreciate any help. Thanks.
>
> O. Lee
ReaplacePart is the way to do this. It workes in this example:
In[9]:=
mat = {{a,b},{c,d}}
Out[9]=
{{a, b}, {c, d}}
In[11]:=
mat = ReplacePart[ mat, 4, {1,2}]
Out[11]=
{{a, 4}, {c, d}}
In[12]:=
mat
Out[12]=
{{a, 4}, {c, d}}
I am not sure what happened in your case - without seeing the exact
messages it is hard to tell.
I hope this helps.
--Ian
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Ian Collier
Technical Sales Support
Wolfram Research, Inc.
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tel:(217)-398-0700 fax:(217)-398-0747 ianc at wri.com
Wolfram Research Home Page: http://www.wri.com/
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