加速这个matlab代码？

Question

有没有一种好方法可以使用矩阵运算或其他任何方法来加速这个 matlab 代码块（尤其是n，可能很大）？我超过 1/4 的执行时间都在这个小代码块中。

% Get the bin indexes that we will place the network in
bins = [];
for n=low_freq:0.5:high_freq;
    bins = [bins, (n-spec_start)/spec_bin_size+1];
end

测试代码：

spec_start=2400
spec_bin_size=0.5
low_freq = 2437
high_freq=2438

bins = [];
for n=low_freq:0.5:high_freq;
    bins = [bins, (n-spec_start)/spec_bin_size+1];
end

bins  % 75 76 77

bins = [];
bins = (low_freq:0.5:high_freq - spec_start)./spec_bin_size + 1;

bins  % empty?

Answer 1

你可以跳过循环：

bins = ((low_freq:0.5:high_freq) - spec_start)./spec_bin_size + 1;

在无法进行上述矢量化计算的情况下，至少应该preallocate the output array