Matlab中arrayfun函数

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arrayfun函数用于对数组中每个元素进行相同的函数操作。
例如，如果进行求平方操作。为避免循环，对于数组可以进行.^操作。即
a=rand(2,2); a2=a.^2; %完成对数组a中每个元素的平方操作。

a=rand(2,2);b=rand(3,3);c=rand(4,4); 如果需要同时对a,b,c数组进行求平方操作。可以通过arrayfun实现

s(1).f1=rand(2,2);s(2).fl=rand(3,3);s(3).f1=rand(4,4);

y=arrayfun(@(x)(x.f1.^2),s,'UniformOutput',false)

以下是MATLAB帮助文档的几个例子。

% To run the examples in this section, create a nonscalar structure array with arrays of different sizes in field f1.s(1).f1 = rand(3, 6);s(2).f1 = magic(12);s(3).f1 = ones(5, 10);% Count the number of elements in each f1 field.counts = arrayfun(@(x) numel(x.f1), s)% The syntax @(x) creates an anonymous function. This code returns% % counts =%     18   144    50 % Compute the size of each array in the f1 fields.[nrows, ncols] = arrayfun(@(x) size(x.f1), s)% This code returns% % nrows =%      3    12     5% ncols =%      6    12    10 % Compute the mean of each column in the f1 fields of s. Because the output is nonscalar, set UniformOutput to false.averages = arrayfun(@(x) mean(x.f1), s, 'UniformOutput', false)% This code returns% % averages = %     [1x6 double]    [1x12 double]    [1x10 double] % Create additional nonscalar structures t and u, and test for equality between the arrays in fields f1 across structures s, t, and u.t = s;  t(1).f1(:)=0;u = s;  u(2).f1(:)=0;same = arrayfun(@(x,y) isequal(x.f1, y.f1), s, t)% This code returns % same =%      0     1     1same = arrayfun(@(x,y,z) isequal(x.f1, y.f1, z.f1), s, t, u)% This code returns % same =%      0     0     1

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