can parfor be used with spectrogram?

I have EEG data and am trying to calculate spectrograms on each channel, then store the data for each channel. It would be nice to use parfor to speed this up, as calculating the spectrogram for each EEG channel should be an independent operation. But, I am getting the error that (for f, t, and p below) "the variable is nondeterministic". Is there some way to fix my code to get this to work, or is the problem with the spectrogram function (part of the signal processing toolbox)?

 parfor this_channel = 1:num_channels    
    [~,f,t,p] = spectrogram(eeg_data(this_channel,:), win_length, num_overlap, nfft, samp_rate);

    f_store(this_channel, :) = f;
    t_store(this_channel, :) = t;
    p_store(:,:, this_channel) = p;
 end

[Jeremy]

I don't currently have the PCT, but what you have looks correct. I have never had really much success with parfor in matlab, however I have seen some dramatic results using the GPU, and this might be a good task for the GPU, especially if "eeg_data" is very large in both dimensions. you could try using cellfun, it would still be single threaded, but it might be faster:

d=num2cell(randn(100000,5),1);
[~,t,f,p]=cellfun(@(x) ... spectrogram(x,hanning(1000),500,1000,1000),d,'uniformoutput',0);

[Imola Fodor]

i had the spectrograms different when i generated them through parfor for a batch of audio files, than from a for loop