如何在单行中将Matlab函数的输出分配给变量? [英] How do I assign the output from a Matlab function to a variable in a single line?

问题描述

matlab中是否有一种方法可以将matlab中的函数的输出分配给一行中的向量?

Is there a way in matlab to assign the output from a function in matlab to a vector within a single line?

例如，此函数应指定周长和面积值

For example, this function should assign a perimeter and an area value

function [p,a] = square_geom(side)
p = perimeter_square(side)
a = side.^2
[p,a]

但是，当我尝试存储这样的数据时

however when I try to store the data like this

v = square_geom(3)

它不起作用.但是，可以这样做

It doesn't work. However it is possible to do it like this

[p,a] = square_geom(3)
v=[p,a]

但这看起来不如将其保持为一行.有什么想法吗?

But that just doesn't look as good as keeping it to a single line. Any ideas?

推荐答案

您可以使用varargout作为输出变量来更改函数的定义:

You can change the definition of your function by using varargout as output variable:

修改 更新了函数的定义，以包括对输出数量的检查

Edit Updated the definition of the function to include the check on the number of output

function varargout = square_geom(side)

p = 3;% %perimeter_square(side)
a = side.^2;
v=[p,a];

switch(nargout)
   case 0 disp('No output specified, array [p,a] returned')
          varargout{1}=v;
   case 1 varargout{1}=v;
   case 2 varargout{1}=p;
          varargout{2}=a;
   case 3 varargout{1}=v;
          varargout{2}=p;
          varargout{3}=a;
   otherwise disp(['Error: too many (' num2str(nargout) ') output specified'])
             disp('array [p,a,NaN, NaN ...] returned (NaN for each extra output)')
             varargout{1}=v;
             varargout{2}=p;
             varargout{3}=a;
             for i=4:nargout
                varargout{i}=NaN
             end
end

这允许您以几种方式调用函数

This allows you either calling your function in several ways

square_geom(3)
v=square_geom(3)
[a,b]=square_geom(3)
[a,b,d]=square_geom(3)
[a,b,d,e,f,g]=square_geom(3)

在第一种情况下，将数组v作为自动变量ans

In the first case you get the array v as the automatic variable ans

square_geom(3)

No output specified, array [p,a] returned
ans =

   3   9

在第二种情况下，获得数组v

In the second case, you get the array v

v=square_geom(3)

v =

   3   9

在第三种情况下，您将获得两个变量

In the third case, you get the two variables

[a,b]=square_geom(3)

a =  3
b =  9

在第四种情况下，您将获得数组v和两个sigle变量a和b

In the fourth case, you get the array v and the two sigle variables a and b

[v,b,d]=square_geom(3)

v =

   3   9

b =  3
d =  9

在后一种情况(指定的输出太多)中，您将获得数组v，两个单个变量a和b以及超出的变量(e，f和g)设置为NaN

In the latter case (too many output specified), you get the array v, the two single variables a and b and the exceeding variables (e, f and g) set to NaN

[v,b,d,e,f,g]=square_geom(3)

Error: too many (6) output specified
array [p,a,NaN, NaN ...] returned (NaN for each extra output)
v =

   3   9

b =  3
d =  9
e = NaN
f = NaN
g = NaN

注意，到目前为止，我已经通过用3

Notice, to thest the code I've modified the function byh replacing the call toperimeter_square with 3

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