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 ----------------------------------------------------------- Ian Collier Technical Sales Support Wolfram Research, Inc. ----------------------------------------------------------- tel:(217)-398-0700 fax:(217)-398-0747 ianc at wri.com Wolfram Research Home Page: http://www.wri.com/ -----------------------------------------------------------