Question

Not quite sure what this means.
“Warning: Matrix is singular to working precision.”

I have a 3×4 matrix called matrix bestM
matrix Q is 3×3 of bestM and matrix m is the last column of bestM

I would like to do C = -Inverse matrix of Q * matrix m
and I get that warning
and C =[Inf Inf Inf] which isn’t right because i am calculating for the camera center in the world

bestM = [-0.0031 -0.0002 0.0005 0.9788;
         -0.0003 -0.0006 0.0028 0.2047;
         -0.0000 -0.0000 0.0000 0.0013];   

Q = bestM(1:3,1:3);
m = bestM(:,4);

X = inv(Q);
C = -X*m;
disp(C);

Answer 1

A singular matrix can be thought of as the matrix equivalent of zero, when you try to invert 0 it blows up (goes to infinity) which is what you are getting here. user 1281385 is absolutely wrong about using the format command to increase precision; the format command is used to change the format of what is shown to you. In fact the very first line of the help command for format says

format does not affect how MATLAB computations are done.