How do I input my data in the correct format to overcome the problem "unable to peform assignment with 0 elements on the right hand side"

I am running matlab on an HPC and wish to create multiple array jobs changing the variable in Examplescript (Opts) to the name of the file in 'testfiles.txt'. I am unable to overcxome the problem "unable to peform assignment with 0 elements on the right hand side" when creating the variable Opts.subject = data{i}.

My code is:

i = getenv('PBS_ARRAY_INDEX')
index = str2num(i)
f = fopen( 'testfiles.txt' )
data = textscan(f, '%s' )
fclose(f)
Opts.subject = data{i}
Opts.subject
Examplescript (Opts)

'testfiles.txt' contains:

003_S_4136
006_S_4192
006_S_4546

Your help would be most welcome.

[Bob Thompson]

The error would seem to indicate that data is an empty array. Are you sure that the textscan command is properly scanning your file?

[AV]

Thank you for your suggestion - it does seem to be scanning the file properly.

Answer 1

[Cris LaPierre]

Your main issue is that, apparently, i is a char. At least you use str2num to convert it when creating index. You should therefore be using 'index' instead of 'i' in your assignment.

Opts.subject = data{index}

However, there is, I suspect, another issue.

data is a 1x1 cell.

data{1} is a 3×1 cell array:

  {'003_S_4136'}
  {'006_S_4192'}
  {'006_S_4546'}

data{1}{index} (where index = 1) is '003_S_4136'.

Your code makes me think you want to pull out the first subject id, not all 3 at once.

[AV]

Thank you - agreed to use index instead. You are correct about the second issue. Is there a way to reformat this to run all 3 at once?

[Cris LaPierre]

Maybe. It all depends on what your code does. What does running all 3 at once mean?