MATLAB: Fast transfer of .net array to matlab array.

arrayimage processingnet

I am calling a .net dll from matlab, which is working just fine. I get an image from the .net dll and then want to process it with matlab, before sending it back to .net. The problem is that most of the matlab functions do not work with the .net array, so I would like to change the .net array to a matlab array, do the processing, and then send it back to .net.
The problem is that I cannot find an efficient way to do this. Indexing the .net array, is painfully slow. There does not seem to be a built in function to do this transfer. Is there a good way to transfer an array of single to a matlab array?

Best Answer

Hi,
actually its pretty fast. Working on that .NET Array directly is not that fast, but converting it into ML data type is fast:
my_array = NET.createArray('System.Single[]',100000);
disp('filling up with values => takes ages')
tic
for i=1:my_array.Length
    my_array(i) = i;
end
toc
disp('convert to ML data type => pretty fast')
tic
ML_dlb_arr = my_array.double;
toc
When running this in MATLAB I get:
filling up with values => takes ages
Elapsed time is 20.732684 seconds.
convert to ML data type => pretty fast
Elapsed time is 0.028037 seconds.
So 0.03seconds for converting 100000 values from .NET to MATLAB is okay I think.
What size does your data have? How long does it takes for you?
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