How to decimate by rows in a dataset ?

Hi I have dataset of 1918975 rows and 10 columns. I need to resample this data without aliasing effect. I found the solution was decimate. But It doesnot work with whole matrix. I only accept vectors. So how can i do this by rows to decimate something like 19189 rows and 10 columns. If there is other method to resample you are welcome to give your idea.

Answer 1

[Image Analyst]

I don't know how you can avoid aliasing completely, but you can subsample like this

smallM = M(startingRow : stepRow : endingRow);

For example to take every other row:

smallM = M(1:2:end);  % Or M(2:2:end);

[Bikram Kawan]

Thank you but. My professor said there will be aliasing effect and the method you recommend i showed him already but was not happy with the output.

[Bikram Kawan]

I was looking something like this http://uk.mathworks.com/help/signal/ref/decimate.html But this function only works for vector. But I need to run for multiple rows.