readimage function throws error in MAtlab 2018a

readimage function with a pixelLabelDatastore argument Throws error

Error using whos
Must be a string scalar or character vector.

Error in categorical/subsref (line 20)
    whos (s.subs{:})

Error in matlab.io.datastore.PixelLabelDatastore.label2cat (line 851)
                C = categoricalCache(uint16(L)+1);

Error in matlab.io.datastore.PixelLabelDatastore/label2categorical (line 789)
                C{i} = matlab.io.datastore.PixelLabelDatastore.label2cat(...

Error in matlab.io.datastore.PixelLabelDatastore/readimage (line 502)
                    C = this.label2categorical(C, info);

Error in Main_2 (line 14)
C = readimage(pxds,1);

[Guillaume]

Can you give the output of:

content = strsplit(fileread(fullfile(matlabroot, 'toolbox', 'matlab', 'datatypes', '@categorical', 'subsref.m')), '\n', 'CollapseDelimiters', false);
content{20}

which is basically line 20 of categorical/subsref. Have you edited that file by mistake?

[Nandagopalan Venugopalan]

Pls find the output below. I haven't edited the particular file.

content = strsplit(fileread(fullfile(matlabroot, 'toolbox', 'matlab', 'datatypes', '@categorical', 'subsref.m')), '\n', 'CollapseDelimiters', false);
content{20}

ans =

      '    whos (s.subs{:})'

Answer 1

[Guillaume]

For some reason, the content of categorical/subsref.m (true path of the file is the output of fullfile(matlabroot, 'toolbox', 'matlab', 'datatypes', '@categorical', 'subsref.m')) has been edited. Line 20 of that file is not what it should be. it looks like somebody was trying to debug the file and left some debug code there. That debug code makes no sense as in most cases it will error and in the rare cases where it doesn't, will output nonsense.

As it's unknown what else has been modified, I would recommend you reinstall matlab unfortunately.

And of course, never modify matlab own m files.

[Nandagopalan Venugopalan]

Hi Guillaume

Thank You... Will do the suggested and keep posted!