Matlab Timing

Timing

MATLAB

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MATLAB 中程序运行计时有以下方法

cputime Method

函数 cputime 返回 MATLAB 启动后 CPU 运行时间, 做差的程序 CPU 运行时间

tic/toc Method

tic, toc 作为一对函数称为 stopwatch timer functions. 基本语法如下

tic
% Code block
toc

tic 记录的时间自动传递给 toc, toc 再返回差值.

当有多对 tic/toc 时, 需要手动记录 tic 并传递给 toc.

timeit

函数 timeit 返回函数运行多次后的平均运行时间, 输入参数为函数句柄.

Remarks

• cputime 返回的是 CPU 时间; timeit 和 tic/toc 返回的是 wall-clock 时间
  • CPU time for the pause function is typically small, but the wall-clock time accounts for the actual time that MATLAB execution is paused
  • The cputime function measures the total CPU time and sums across all threads
    • If your function uses four processing cores equally, the CPU time could be approximately four times higher than the wall-clock time
• Unlike tic/toc, the timeit function calls your code multiple times, and, therefore, considers first-time costs