xlsread - Reading set number of columns with unknown number of row...

If I use xlsread with no range it takes 45 sec to read file and returns n cols x 65k rows for my file.

If I read just the columns I need by 65k it takes 20 sec to read the data I need.

Every workbook and every sheet in workbooks have a different unknown number of rows of data. So for efficient processing I would like to read columns A:D all rows for every sheet I have to process, without having to look at each sheet interactivly.

If I look at the file, there are 65k rows, if I use the active x to find the number of rows, it returns 65k as the end row. However reading the data I need with the activex takes longer than reading with xlsread and no range.

The solution would be to use xlsread and just specify the col information. (ie read a single col by specifing range C:C. However when I do this xlsread returns over a million rows of data not the 65k that are in the file. This causes a not enough store error.

Is there a way to get the faster xlsread to work properly? Adam (2011a)

Answer 1

[Oleg Komarov]

Strange, for me it works fine:

xlsread('test.xlsx',1,'A:D')

[Adam]

That would point to something wrong with all my excel files, however if that was the case, why would...

rowEnd = sheetObj.Range('A1').End('xlDown').Row

return the correct number of rows...

[Adam]

ps also...

xlsread('test.xlsx',1)

returns the correct number of rows as well...

[Oleg Komarov]

can you upload one of the problematic files somewhere or send to my mail?

[Franck Dernoncourt]

I have the same issue. Here is an example of a file causing the issue: http://www9.zippyshare.com/v/67423126/file.html

The file has only 272 rows, but using [~, ~, temp] = xlsread('1.csv','A:A'); temp will have dimension 1048576x1.

Any idea what is causing this issue? I use Win7 + MATLAB 2012a

I have no issue when using textscan:

fid = fopen('1.csv','r');
datatemp = textscan(fid, '%s %d %d %d %s %s %s %s %s %d %d', 'delimiter',',', 'CollectOutput',true, 'headerLines', 1)
fclose(fid);

[Franck Dernoncourt]

More details on the above-mentioned issue here: http://stackoverflow.com/q/16700909/395857