Issues with comparing data read in form Excel (equals to)

Hello, this is my first post and hope someone can help.

I am writing a shot piece of code but I am coming up against a brick wall with an error.

Below is the code I have written.

%% Load txt file into Matlab

M = uigetfile('*.xlsx','Select the .xls-file'); % This get the file name only and puts it in M

[data,text] = xlsread(M); %data captures the "time" but converts it to number - test saves the rest

% M is the selected file that is read in

time = data*24;

% File now loaded into Matlab - Time not accurate but will still allow us

% to distinguish between one transmission bloak and the next

%% While loop -

d = ' ';

i = 1;

while d == ' '

    i = i + 1;      % i should equal 2 after first run
    d = text(i,1);  % row i, column 1 of the text read in
end

Below is the fail I am getting:

%??? Undefined function or method 'eq' for input arguments of type 'cell'.

%Error in ==> WAL_Analyser at 21

%end

I have tried different types of brackets, and spent hours trying different thing but couldnt find code that works.

Any questions let me know... the first few cells I would be looking at in the loop would be blank then when i = 6 I should receive text, and exit the loop. Thats what I had hoped anyway.

Thanks, Sean

Answer 1

[Titus Edelhofer]

Hi,

the problem is the line

d = text(i,1);

which makes d a 1x1 cell array (for which the == fails, see error message). You should get the cell entry with curly braces:

d = text{i,1};

Second: you are comparing strings, but the == compares elementwise. So when d is not empty, the d=='' will fail again. Better: use

while isempty(d)

Titus

[Titus Edelhofer]

And by the way: using find(~cellfun(@isempty, text(:,1)), 1, 'first') should give you the index you are searching for ...

Titus

[Sean]

Ah I was going to say it still doesnt work, but after changing the line d = ' ' to d = '', taking out the space and making d "empty", it works, I now get my text assigned to d when i = 6 and exit the loop.

Also tried the second way, also works to list the cells which aren't empty.

Every day is a school day.

100% happy I came on here. Thanks Titus, you were very helpful