Write image cube in BIP format

I am trying to write a 3-D image cube or 3-D matrix to a file that can be read in ENVI. When I open the file that I wrote from MATLAB in ENVI the image only displays correctly when the header file has the samples and lines switched and the interleave is BSQ. I need the interleave to be BIP and the samples and lines to be correct. I suspect that matlab writes to file by writing all rows and columns of band 1, then all rows and columns of band 2, etc. I need it to write row 1, column 1, all bands; row 1, column 2 all bands, etc. any ideas how to do this? Here is the partial code:

eventIDStr = num2str(eventID);

fwriteid = fopen([eventIDStr '_sav.dat'],'w');

count = fwrite(fwriteid,cube,'single');

status = fclose(fwriteid);

Thank You

Answer 1

[Walter Roberson]

MATLAB writes in its indexing order, which is down the columns first. You have to pass fwrite() an expression which will give you the desired result when the expression is written down-first.

It appears to me that perhaps

permute(cube,[3 1 2])

would be the expression to pass to fwrite()