How should I solve "ranges for MatFile objects must increase in equally spaced intervals"?

I want to read some specific rows from a large data file (a large matrix in .mat format). The codes are as follows

m = matfile('data_file.mat'); % a N*D matrix data is stored in 'data_file.mat'
xx = m.data([1,3,4,6,9],:);

The error alert is "Cannot index into 'data' because ranges for MatFile objects must increase in equally spaced intervals". Is there any solution to this problem?

Answer 1

[Image Analyst]

You forgot to attach your .mat file so we can't try your code. But try breaking it up into two lines

% Extract 2-D matrix into xx
xx = m.data; 
% Now extract only specified rows.
xx = xx([1,3,4,6,9],:);