fopen is returning ''

Hello,

While I am trying to open a file using fopen the file id is returning ''.

I am attaching the error here, when using the whole file location it is working fine but when giving variables its not.

fopen(strcat(DirPath,'/',SbjList{1}(1,:),'/',SbjList{2}(1,:),'/FREESURFER/stats/aseg.stats'))

ans =

     ''

K>> strcat(DirPath,'/',SbjList{1}(1,:),'/',SbjList{2}(1,:),'/FREESURFER/stats/aseg.stats')

ans =

    '/raid6/data9/CSP4REST/FS5.1_RES_5/5002/tp1/FREESURFER/stats/aseg.stats'

K>> fopen('/raid6/data9/CSP4REST/FS5.1_RES_5/5002/tp1/FREESURFER/stats/aseg.stats')

ans =

    12

Answer 1

[Walter Roberson]

strcat() is returning a cell array that contains the string. You cannot fopen() a cell array.

I would suspect that DirPath is a cell array containing one string.

I suggest you use

[fid, message] = fopen(strcat(DirPath,'/',SbjList{1}(1,:),'/',SbjList{2}(1,:),'/FREESURFER/stats/aseg.stats'))

and look at the message generated.

If I am correct in my suspicion, changing to DirPath{1} should fix the problem.

Answer 2

[Mohan]

Hello Walter,

Thanks for the information but still when I debugging it, DirPath is just a variable having the path. When I give it in command window the following result popped up.

K>> DirPath

DirPath =

/raid6/data9/CSP4REST/FS5.1_RES_5.

and when I give DirPath{1} it showed an error

??? Cell contents reference from a non-cell array object.

and when I used [fid, message], both of them returning null ('').

[Walter Roberson]

In any case, the strcat() is returning a cell array. You can see that by examining your output and examining the output differences for the following two expressions:

'Hello'

{'Hello'}