Hi, For the sake of consistency, I've copied your matrix in python sympy and got the following result for the inverse of A : Matrix([ [ gm/(gm/R2 + gm/R1), 0, 0, 0, -R1*(gm*(gm/R2 + gm/R1) - gm**2/R2)/(gm*(gm/R2 + gm/R1)), gm/(gm/R2 + gm/R1), 0, 0, -R1*(-gm*(gm/R2 + gm/R1)/R1 + gm**2/(R1*R2))/(gm*(gm/R2 + gm/R1))], [ 0, 0, 0, 0, 0, 0, 0, 0, 1], [ Ro*gm**2/(gm/R2 + gm/R1), 0, Ro, 0, R1*Ro*(-gm*(gm/R2 + gm/R1) + gm**2/R2)/(gm/R2 + gm/R1), Ro*gm**2/(gm/R2 + gm/R1), Ro, 0, -Ro*gm**2/(R2*(gm/R2 + gm/R1))], [-Rs*gm**2/(gm/R2 + gm/R1), 0, 0, Rs, -R1*Rs*(-gm**2*(gm/R2 + gm/R1) + gm**3/R2)/(gm*(gm/R2 + gm/R1)), -Rs*gm**2/(gm/R2 + gm/R1), 0, Rs, Rs*gm**2/(R2*(gm/R2 + gm/R1))], [ -gm/(R1*(gm/R2 + gm/R1)), 0, 0, 0, -gm/(R2*(gm/R2 + gm/R1)), -gm/(R1*(gm/R2 + gm/R1)), 0, 0, gm/(R1*R2*(gm/R2 + gm/R1))], [-gm/(R2*(-gm/R2 - gm/R1)), 0, 0, 0, gm/(R2*(-gm/R2 - gm/R1)), gm/(R1*(-gm/R2 - gm/R1)), 0, 0, -gm/(R1*R2*(-gm/R2 - gm/R1))], [ gm**2/(gm/R2 + gm/R1), 0, 1, 0, R1*(-gm*(gm/R2 + gm/R1) + gm**2/R2)/(gm/R2 + gm/R1), gm**2/(gm/R2 + gm/R1), 0, 0, -gm**2/(R2*(gm/R2 + gm/R1))], [ -gm**2/(gm/R2 + gm/R1), 0, 0, 1, -R1*(-gm**2*(gm/R2 + gm/R1) + gm**3/R2)/(gm*(gm/R2 + gm/R1)), -gm**2/(gm/R2 + gm/R1), 0, 0, gm**2/(R2*(gm/R2 + gm/R1))], [ gm/(R1*(gm/R2 + gm/R1)), 1, 0, 0, gm/(R2*(gm/R2 + gm/R1)), gm/(R1*(gm/R2 + gm/R1)), 0, 0, -gm/(R1*R2*(gm/R2 + gm/R1))]]) Seems to me there is a bug somewhere in GiNaC. jmt On Sun, 07 Jan 2018 17:08:18 +0100 Patrick Schulz <pschulz@posteo.de> wrote:
Hi,
i'm getting a segmentation fault while inverting a matrix (the matrix itself is invertable, i checked with the symbolic package for octave). Can anyone give me some pointers why this is happening? Is the matrix ill-formed in some way or is this a bug? Many thanks in advance!
I'm running archlinux (Kernel 4.14.12), my compiler is g++ 7.2.1, the GiNaC version i'm using is 1.7.2.
Attached is a sample listing which produces the error (at least on my system).
Greetings, Patrick
-- Jean-Marie Thomas http://www.dxdydz.net