Question

I’m trying to find something similar in MATLAB to PyTables’ table.where that selects a subset of a dataset based on criteria (such as col1 = 4). So far, my searching has been completely fruitless. I can’t believe such a useful feature wouldn’t be supported somehow… can anyone help?

MATLAB ver R2011b.

EDIT: In case it wasn’t clear from the question, I’m using an HDF5 file for data storage in MATLAB, hence my desire to find functionality similar to PyTables.

Answer 1

I think what you try to do involves either load-ing the file in memory (or you might give HDF5 Diskmap Class a try if it’s to big for memory).

Once you have access to your data in matlab as a matrix, it’s easy as:

a=[
0 0 0 0 1;
0 1 0 0 1;
1 0 1 1 1;
0 1 1 1 1;
1 0 1 0 1];

a(find(a(:,1)==1),:)