Question

我对MATLAB中的并行计算很新，我面临以下问题：我有以下脚本迭代调用优化函数

trials = cell2struct([ ...
    {     4      5      6      7     10      16     17     18      23     24}; ...
    {   0.5      1    0.5      0      0     0.5    0.5    0.5     0.5      0}; ...
    {     0      0     pi     pi      0 pi-pi/6  -pi/6   pi/6 pi+pi/6   pi/6}; ...
    {0.0458 0.0440 0.0510 0.0312 0.0464  0.0449 0.0461 0.0598  0.0598 0.0511} ], ...
    {'idx', 'mounting', 'q5_0', 'dq4_squared'}, 1);

coeff = [2, 10.5, 20, 25, 2.5];

while < some_stop_condition >
    [coeff, fval] = fminunc(@(x) EvaluateIndex(x, trials), coeff);
end

我有一个函数EvaluateIndex的工作顺序版本，但由于执行计算需要很长时间，所以我想切换到并行版本。 “并行化”目标函数EvaluateIndex的简化版如下：

function MeanSquaredError = EvaluateIndex(coeff, configs)
    % Simulation time
    dT      = 0.01;                     % Time step [s]
    T_final = 60;                       % Duration  [s]

    % Wave characteristics
    wave = SeaWave( < sea_wave_params > );

    % Vehicle settings
    for i = 1:length(configs)
         vehicle(i) = PrototypeWAVE( < vehicle_i_params > );
    end

    dq4_squared = zeros(1, length(configs));

    tic
    parfor i = 1:length(configs)
         % Initial conditions
         q1_0 = 0;
         q2_0 = 0;
         q3_0 = 0;
         q4_0 = pi/2;
         q5_0 = configs(i).q5_0;
         q_0  = [ q1_0+1.3*(1-cos(q3_0)), q2_0+1.3*sin(q3_0), q3_0, q4_0, q5_0 ]';
         dq_0 = [ 0, 0, 0, 0, 0 ]';

         % Run simulation
         [~, Results] = Run(vehicle(i), wave, [q_0; dq_0], dT, T_final);

         % Get results
         dq4_squared(i) = mean(Results(:,9).^2);
    end
    toc

    MeanSquaredError = sum( (dq4_squared - horzcat(configs.dq4_squared)).^2 );
end

此处，SeaWave和PrototypeWAVE是两个类，函数Run是PrototypeWAVE类的方法。根据我发现的一些建议，我在parfor循环之外定义了这些类的对象;但是，当我尝试运行脚本时，我收到以下警告：

Warning: Element(s) of class 'SeaWave' do not match the current constructor definition.  The element(s) have been converted to structures.
Warning: Element(s) of class 'PrototypeWAVE' do not match the current constructor definition.  The element(s) have been converted to structures.

并出现此错误：

Error using EvaluateIndex (line 75)
Cannot find an exact (case-sensitive) match for 'Run'

The closest match is: run in /Applications/MATLAB_R2016b.app/toolbox/matlab/lang/run.m

似乎MATLAB无法识别类及其方法的存在。我已经尝试在addAttachedFiles(gcp, {'./@SeaWave', './@PrototypeWAVE'})循环之前添加行parfor，但没有任何变化。

我在MACOS上使用MATLAB R2016b。

非常感谢任何帮助。提前致谢

在parfor循环中使用用户定义的对象时出现问题

0 个答案: