Is it faster to use array size as an input or calculate size

Question

Josh 2015-4-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/197175-is-it-faster-to-use-array-size-as-an-input-or-calculate-size

编辑： James Tursa 2015-4-10

I have a function which will be called many times and performs operations on an array. The function is dependent on the size of the array. Is it faster to calculate the size before implementing the function, or just use the size command as the first step of the function? Thanks

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

James Tursa 2015-4-10

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/197175-is-it-faster-to-use-array-size-as-an-input-or-calculate-size#answer_174753

编辑：James Tursa 2015-4-10

For ease of use, typically the size would be generated inside the function to make sure there was no mismatch. For speed, this choice is likely in the noise and may not matter where you do it. How simple is your function? Does the array argument change size during the execution of the program? Etc. If you are concerned about speed then use the profiler to determine where to concentrate your efforts. It is probably not with that line.