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Topic: ReplacePart
Replies: 4   Last Post: Sep 15, 2013 7:04 AM

 Messages: [ Previous | Next ]
 Itai Seggev Posts: 61 Registered: 7/29/13
Re: ReplacePart
Posted: Sep 15, 2013 6:57 AM

On Sat, Sep 14, 2013 at 06:02:59AM -0400, man21 wrote:
> Hello,
>
> As a result of a calculation, I end up with a list of numerical values
> which contains some "Indeterminate".
>
> x ={-1.25664, 0.628319, -0.628319, 1.25664, Indeterminate, -1.25664,
> 0.628319, -0.628319, 1.25664, Indeterminate}
>
> I try to replace the "Indeterminate" by "0", using :
>
> ReplacePart[x, {5, 10} -> 0.]
>
> but this dosen't work. Any idea why, and how to do it ?

A flat list in ReplacePart is interpreted as a single multi-level part
specification. For example,

In[282]:= ReplacePart[Array[a, {2, 2}], {1, 2} -> 0.]

Out[282]= {{a[1, 1], 0.}, {a[2, 1], a[2, 2]}}

What you want is this.

In[280]:= ReplacePart[x, {{5}, {10}} -> 0.]

Out[280]= {-1.25664, 0.628319, -0.628319, 1.25664, 0., -1.25664, \
0.628319, -0.628319, 1.25664, 0.}

I think in any event it is easier and better to use ReplaceAll

In[283]:= x /. Indeterminate -> 0.

Out[283]= {-1.25664, 0.628319, -0.628319, 1.25664, 0., -1.25664, \
0.628319, -0.628319, 1.25664, 0.}

--
Itai Seggev
Mathematica Algorithms R&D
217-398-0700

Date Subject Author
9/15/13 Sseziwa Mukasa
9/15/13 Itai Seggev