Re: what is wrong here?
- To: mathgroup@smc.vnet.net
- Subject: [mg12144] Re: [mg12103] what is wrong here?
- From: "Jürgen Tischer" <jtischer@pitagoras.univalle.edu.co>
- Date: Mon, 27 Apr 1998 01:46:26 -0400
Hi Rao,
all I can say that your example causes no problem on my Win95 PC.
J|rgen
-----Original Message-----
From: Dr. Jagannatha Rao <rao@supermod.egr.uh.edu> To:
mathgroup@smc.vnet.net
Subject: [mg12144] [mg12103] what is wrong here?
>
>I am having a lot of difficulty in trying to use commands on a matrix as
>follows:
>
>matrix[[{i,j,k},{i,j,k}]] = matrix[[{i,j,k},{i,j,k}]] + some 3x3 matrix.
>
>See the example below. When i,j,k areconsecutive indices, there seems
>to be no problem. When the indices are, say {3,4,7,8}, the program
>always crashes with a bus error.
>
>----------------------------------------------------------
>
>
>supermod 103$ math
>Mathematica 3.0 for NEXTSTEP Intel
>Copyright 1988-97 Wolfram Research, Inc.
> -- Motif graphics initialized --
>
>In[1]:= matrix = Table[a , {i,8},{j,8}]
>
>Out[1]= {{a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a}}
>
>In[2]:= matrix[[{1,2,3,4},{1,2,3,4}]] //MatrixForm
>
>Out[2]//MatrixForm= a a a a
>
> a a a a
>
> a a a a
>
> a a a a
>
>In[3]:= temp=Table[b, {i,4},{j,4}]
>
>Out[3]= {{b, b, b, b}, {b, b, b, b}, {b, b, b, b}, {b, b, b, b}}
>
>In[4]:= matrix[[{1,2,3,4},{1,2,3,4}]] = \ matrix[[{1,2,3,4},{1,2,3,4}]]
>+ temp
>
>Out[4]= {{a + b, a + b, a + b, a + b}, {a + b, a + b, a + b, a + b},
>
>> {a + b, a + b, a + b, a + b}, {a + b, a + b, a + b, a + b}}
>
>In[5]:= matrix //MatrixForm
>
>Out[5]//MatrixForm=
>
>> a + b a + b a + b a + b a a a a
>
> a + b a + b a + b a + b a a a a
>
> a + b a + b a + b a + b a a a a
>
> a + b a + b a + b a + b a a a a
>
> a a a a a a a a
>
> a a a a a a a a
>
> a a a a a a a a
>
> a a a a a a a a
>
>In[6]:= matrix = Table[a , {i,8},{j,8}]
>
>Out[6]= {{a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a},
>
>> {a, a, a, a, a, a, a, a}, {a, a, a, a, a, a, a, a}}
>
>In[7]:= matrix[[{3,4,7,8},{3,4,7,8}]]= \ matrix[[{3,4,7,8},{3,4,7,8}]] +
>temp Bus error
>supermod 104$
>
>
>--
>Jagannatha Rao E-mail:rao@uh.edu
>Associate Professor
>Department of Mechanical Engineering Tel :(713) 743-4535 University
>of Houston Fax :(713) 743-4503 Houston, TX
>77204-4792
>
>