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Re: Re: More on Delete Problems

• To: mathgroup at smc.vnet.net
• Subject: [mg51624] Re: [mg51610] Re: More on Delete Problems
• From: Andrzej Kozlowski <andrzej at akikoz.net>
• Date: Wed, 27 Oct 2004 23:42:09 -0400 (EDT)
• References: <cl9t75$7nl$1@smc.vnet.net> <200410270554.BAA24546@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Packed Arrays strike again!

Try this:


In[1]:=
a = {{1., 2., 3.}, {4., 5., 6.}};

In[2]:=
b = {{1, 0, 1}, {0, -2, 3}, {0, 1, 0}};

In[3]:=
c = Developer`FromPackedArray[a . b];

In[4]:=
Delete[c, {1, 1}]

Out[4]=
{{-1., 7.}, {4., -4., 19.}}

No crash.

Andrzej Kozlowski

Andrzej Kozlowski
Chiba, Japan
http://www.akikoz.net/~andrzej/
http://www.mimuw.edu.pl/~akoz/




On 27 Oct 2004, at 14:54, Peter Valko wrote:

> For the record:
>
> $Version
> 5.0 for Microsoft Windows (June 11, 2003)
>
> a={{1.,2.,3.},{4.,5.,6.}}
> b = {{1,0,1},{0,-2,3}, {0,1,0}}
> c = a . b
> Delete[c,{1,1}]
>
> crashes Mathematica on my machine, exactly as Give Effinger said.
>
>
>
>
>
>
>
>
> Gove Effinger <effinger at skidmore.edu> wrote in message 
> news:<cl9t75$7nl$1 at smc.vnet.net>...
>> Here's simple code which bombs for me:
>>
>> a={{1.,2.,3.},{4.,5.,6.}}
>>
>> b = {{1,0,1},{0,-2,3}, {0,1,0}}
>>
>> c = a . b
>>
>> Delete[c,{1,1}]
>>
>> Why?
>>
>> G. Effinger
>
>

• References:
  • Re: More on Delete Problems
    • From: p-valko@tamu.edu (Peter Valko)