Re: Why does Inverse[M] hesitate?
- To: mathgroup at smc.vnet.net
- Subject: [mg54460] Re: Why does Inverse[M] hesitate?
- From: Peter Pein <petsie at arcor.de>
- Date: Sun, 20 Feb 2005 00:11:35 -0500 (EST)
- References: <cv6t0c$6re$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Skirmantas wrote:
> The Inverse function sometimes calculates the inverse of a matrix
> immediately, sometimes it does not. Try this example in Mathematica
> 5.1:
>
> A={{(1-g)-1,1},{-w P(1-g)/C,-1}}//MatrixForm
> B={{0},{-P(w+1)}}//MatrixForm
>
> I get
> Out: Inverse[(expanded A)].(expanded B)
>
> If I do just
> A={{a,b},{c,d}}
> B={{e},{f}}
> Inverse[A].B
>
> I get the final correct result.
>
Inverse and Dot are not defined for MatrixForm[{{...}}].
Enter
( A={{(1-g)-1,1},{-w P(1-g)/C,-1}} )//MatrixForm
( B={{0},{-P(w+1)}} )//MatrixForm
and it will work as expected.
--
Peter Pein
Berlin