Date conversion program error

I have a program that finds the time column in a data sheet (in unix time) and takes each time value and makes a new excel document and converts it into the hour.

Here's the code I made for it: fileid=['sitedata.csv']; [data, text] = xlsread(fileid); col = strcmpi(text(1,:),'Time'); A = data(:,col); for i = 1:length(A) X = datenum([1970 1 1 0 0 A(i)]); hour = datestr(X, 'HH'); A(i) = hour; end

When I run it the error I get is: ??? In an assignment A(I) = B, the number of elements in B and I must be the same.

Error in ==> time at 28
        A(i) = hour;

Any ideas how to fix this? Thank you!

Answer 1

[Fangjun Jiang]

In your code, "A" is a double array, "hour" is a char array. If you change A(i)=hour to B{i}=hour, it will work. But it's better to pre-allocate B as a cell array right before the for-loop B=cell(size(A));

[Michael]

With the first method, it's now giving this error:

??? Cell contents assignment to a

non-cell array object.

Error in ==> time at 28

A{i} = hour;

[Fangjun Jiang]

No. You can't re-use the variable A. Try to make a different variable B.