How can I read a value from a .xls file based upon when a specific digit in a specific column changes value?

Hello, I am trying process a data file with over 19000 entries (coordinates and timestamp) for eventual use in a simulator device with maximum 12000 entries, so I need to sample the data file

Simply reading every Nth entry won't do the job since there are inconsistencies in the timestamps. These timestamps are 8 digits; I would like to read data only when the 5th (012345678) digit increments

Is there a matlab function for this kind of data processing?

Thanks Gavin

[Nick Hobbs]

I understand you want to process information in a file based on a condition within that file. One way to do this would be to use 'fgetl' which can read a file 1 line at a time. You could use this function, and then only keep the line of data if the condition has been met. You can find more information on 'fgetl' at the following link.

http://www.mathworks.com/help/matlab/ref/fgetl.html

[Gavin Davis]

ah I see! Thanks!

[Gavin Davis]

I can't accept this as an answer since it was posted as a comment, but if you resubmit as an answer I will, if it matters to you that is :-)