reading specific data from a ascii file

HI everyone,

I am trying to access and import a part of a very large file (.ascii format) in matlab workspace. I tried with two approaches: 1. 'dlmread' but the exported data converts the -ve values into zero. I tried with changing the format with 'format long e' but no success. 2. fid = fopen('C:\s4.ascii'); format = repmat('%f', [1 nCols]); c = textscan(fid, format); here the problem is 'How to get a particular range of columns and rows in to matlab?'

Any help.

Thanks in advance.

Answer 1

[Titus Edelhofer]

Hi,

for the columns you can use %*f to skip a column. Building the format string will be slightly more complicated of course, depending on which columns you want to have...

Second, for the rows, take a look at the third parameter 'N' for reading a specified number of rows and look for 'headerlines' to skip a specified number of rows ...

Titus

[Vinay Kumar]

Hi Titus, %*f is not working. I mean, it doesn't skips the lines. Could you please shed some more light to your solution. Thanks.

[Titus Edelhofer]

Hi Vinay,

the %*f skips a column, not a line. For reading only a particular set of lines you would call textscan several times with using the "headerlines" parameter to skip a number of lines.

Titus