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Matlab warning points to the wrong line

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Alexandru
Alexandru on 29 Oct 2014
Commented: Alexandru on 29 Oct 2014
Hello,
I am executing an m-file using Matlab 2014b. Let's call it my_m_file. During the execution I am getting the following warning:
Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 3.277288e-17. > In viaMtimes at 35 In my_m_file at 35
I understand the warning and at line 35 in the file viaMtimes one has: "Z = inv(Z);". It is true that at several points in my code I am raising a matrix to the power -1 and I understand that on one such occasion the matrix is close to singular so the inversion is problematic.
Normally the last part of the message "In my_m_file at 35" would point out to the line in my m file where the problem lies. But this is where it gets strange. On line 35 of the file I am actually declaring a new variable as M = NaN(T,N) where T and N have been previously defined. What causes Matlab to point to the wrong line and how can I fix this?
Thanks,
Alex

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Answers (2)

Andreas Goser
Andreas Goser on 29 Oct 2014
I can think of an effect where you have multiple files with the same name on the path like previous versions or a pcoded file. You can test this with
which my_m_file -all
I also wonder if the effect is reproducible on other machines/installations?

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Alexandru
Alexandru on 29 Oct 2014
I tested for the same name on the path using your command and it produced a single output: the path to the current file. I also tried renaming the file, but that didn't work either.
I will see to what extent I can run the code on a different machine.

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Robert Cumming
Robert Cumming on 29 Oct 2014
This could also happen if your file is locked by mlock. If you restart Matlab does the problem remain?

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Alexandru
Alexandru on 29 Oct 2014
I tried a restart both of Matlab and the computer. That didn't fix it.

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