Re: Mathematica bug??
- To: mathgroup at smc.vnet.net
- Subject: [mg100583] Re: Mathematica bug??
- From: Erik Max Francis <max at alcyone.com>
- Date: Mon, 8 Jun 2009 03:05:59 -0400 (EDT)
- References: <h0fvlb$rct$1@smc.vnet.net>
oshaughn wrote:
> {{Sqrt[1 - 2/r], 0, 0, 0}, {0, 1/Sqrt[1 - 2/r], 0, 0}, {0, 0, r,
> 0}, {0, 0, 0, r Sin[\[Theta]]}} // Inverse
>
> gives
>
> {{0, 0, 0, 0}, {0, 0, 0, 0}, {0, 0, 1/r, 0}, {0, 0, 0, Csc[\[Theta]]/
> r}}
>
> with no warnings. This is a *diagonal* matrix that should be
> trivially invertible.
>
> Does anyone know why Inverse has catastrophically failed here?
For what it's worth, it works properly here:
In[8]:= {{Sqrt[1 - 2/r], 0, 0, 0}, {0, 1/Sqrt[1 - 2/r], 0, 0}, {0, 0,
r, 0}, {0, 0, 0, r Sin[\[Theta]]}} // Inverse
Out[8]= {{1/Sqrt[1 - 2/r], 0, 0, 0}, {0, Sqrt[1 - 2/r], 0, 0}, {0, 0,
1/r, 0}, {0, 0, 0, Csc[\[Theta]]/r}}
In[9]:= $Version
Out[9]= "7.0 for Linux x86 (32-bit) (January 30, 2009)"
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