Matlab中cellfun函数的使用

时间:2024-01-20 14:53:33
Compute the mean of each vector in cell array C.

C = {1:10, [2; 4; 6], []};

averages = cellfun(@mean, C)
This code returns averages =
5.5000 4.0000 NaN

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  该函数就是专门对cell数组进行操作的,个人认为是代替了传统的for循环,和C语言不一个思想,主要是行列化矩阵,一次处理。

  比如a = {[1 2 3] [4 5 6]},那么cellfun(@length,a)得到6。线cell2mat也可以吧,然后分别计算,在累加。

Compute the size of each array in C, created in the previous example.

[nrows, ncols] = cellfun(@size, C)
This code returns nrows =
1 3 0
ncols =
10 1 0

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  cellfun中使用自定义函数对cell数组进行处理;既然可以自定义函数,那么cellfun中的的中间部分的参数个数和自定义函数需要的参数数目相同。

  还能这么用。

queryNearestNeighborIds = cellfun( @(vector, index) vector(index), queryCandidateIds, queryNearestNeighborIds, 'UniformOutput', false );
	

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Create a cell array that contains strings, and abbreviate those strings to the first three characters. Because the output strings are nonscalar, set UniformOutput to false.

days = {'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday'};

abbrev = cellfun(@(x) x(1:3), days, 'UniformOutput', false)
The syntax @(x) creates an anonymous function. This code returns abbrev =
'Mon' 'Tue' 'Wed' 'Thu' 'Fri'