Using dir command but the files can not be returned

After running the code, fileNames1 has not been showing in Workspace (neither name nor value) and there is no error in the first line. However, it gives an error while executing the second line "Undefined function or variable 'numGM'.

code:

FIRST LINE: fileNames1 = dir ('./GMdata/GMsDir/*hc.txt');

SECOND LINE: numGM=length(fileNames1);

[Jan]

What does "after running the code" mean, if the program stops with an error? Please post the relevant part of the code and a copy of the complete error message.

[Mos_bad]

Undefined function or variable 'numGM'.

Error in PBSS_Bridge_Main (line 196) p_ = randperm(numGM);

It gives me three above lines as the complete error message. I mean, if I run the code ....

Answer 1

[Jan]

In line 2 you define

numGM = length(fileNames1)

and in line 196 the variable numGM does not exist anymore. This can have different reasons. Either these are two different functions. Or there is a clear numGM anywhere, or even worse a clear all, perhaps in a called script. Without seeing the relevant code, there is no chance to guess, what happens. But you can examine this in detail using the debugger:

• https://www.mathworks.com/help/matlab/debugging-code.html
• https://www.mathworks.com/help/matlab/matlab_prog/debugging-process-and-features.html

Set a breakpoint in the code and step through the program line by line. Check the existence of the vanishing variable to narrow down, where this happens. The debugger is the programmer's best friend.