par_resample.m

function y = par_resample(x, p, q)
%PAR_RESAMPLE Resample data using parallel computing.
%   Y = PAR_RESAMPLE(X, P, Q) is a drop-in replacement for the
%   standard RESAMPLE(X, P, Q) function. If GNU Octave and the 'Parallel'
%   package are available, it uses multiple CPU cores. Otherwise, it falls
%   back to RESAMPLE(X, P, Q).

%   Copyright (c) 2017, Sebastian Berger.
%
%   Klinikum rechts der Isar der
%   Technischen Universitaet Muenchen
%   Munich, Germany
%
%   All rights reserved.
%
%   Redistribution and use in source and binary forms, with or without
%   modification, are permitted provided that the following conditions are
%   met:
%       * Redistributions of source code must retain the above copyright
%         notice, this list of conditions and the following disclaimer.
%       * Redistributions in binary form must reproduce the above copyright
%         notice, this list of conditions and the following disclaimer in
%         the documentation and/or other materials provided with the
%         distribution.
%       * Neither the names of the copyright holders nor the names of its
%         contributors may be used to endorse or promote products derived
%         from this software without specific prior written permission.
%
%   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
%   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
%   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
%   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR
%   THE KLINIKUM RECHTS DER ISAR BE LIABLE FOR ANY DIRECT, INDIRECT,
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%   BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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%   THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
%   DAMAGE.

if ~isoctave()
    % Do not use parallelisation in MATLAB.
    y = resample(x, p, q);
else
    pkg('load', 'signal');
    try
        % Try to process in parallel.
        pkg('load', 'parallel');
        fcn = @(n) resample(x(:, n), p, q);
        y = pararrayfun(nproc(), fcn, 1:size(x, 2), 'VerboseLevel', 0);
    catch
        % Fall back to single core processing.
        y = resample(x, p, q);
    end
end