Ramón Casero Cañas on Thu, 19 Dec 2002 11:16:49 +0100

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Re: don't understand inverseimage

Bill Allombert wrote:
On Tue, Dec 17, 2002 at 11:10:42PM +0100, rcasero@tsc.uc3m.es wrote:

matinverseimage(A,Y) return a solution of AX=Y if it exists, and [;] else.

Um, I have another question linked to Bill's answer. Let's say the matrix is invertible. Each time that a vector's inverse image is to be computed, the matrix has to be inverted (or whichever process it follows), isn't it? That doesn't seem efficient from a computational point of view (and I'm not saying that that function was written with that idea, or maybe it's more efficient that way than inverting the matrix and then use the inverse as a linear mapping, I don't know). I've been reading other functions descriptions, and I haven't found anything like "inverse(A)".



                Ramón Casero Cañas

              Ing. de Telecomunicación.
          Universidad Carlos III de Madrid