Passing array arguments to an anonymous function

I have an anonymous function, for example

f = @(x,y)x.^2.*y.^2

In general for my problem I don't know how many arguments f will have. Nor do I know how many elements each argument will have.

I want to pass in a single element as an argument. If x and y are scalars, I can define z = num2cell(x,y), then write

f(z{:})

But if x and y are vectors this doesn't work. I could write

for ii=1:2; z = { x(ii);y(ii) }; f(z{:}) ;end

but of course I want to avoid the loop.

Is there some efficient way to obtain what I want by writing something like

f(q{:})

where q{:} is a cell array with each cell containing a vector rather than a scalar.

[Walter Roberson]

num2cell(x,y) is not the same thing as {x,y} when x and y are scalars. Instead num2cell(x,y) says to use y as the dimension number for the num2cell(x) operation.

Answer 1

[Walter Roberson]

It appears to me that what you want is arrayfun:

arrayfun(f, x, y)

[Leo Simon]

Thanks Walter, this is really helpful. For the benefit of anybody else reading, I'm expanding on your answer, to deal with my problem in which the function f has a variablenumber of arguments.

In my case, f could be

f = @(x1,x2,x3)[ prod(x1*x2*x3);prod(x1*x2*x3)]

or

f = @(x1,x2,x3,x4)[prod(x1*x2*x3*x4);prod(x1*x2*x3*x4)];

where the xi's could be scalars or row vectors.

I want to be able to input a single argument that works for both.

The following works:

X = rand(4,3);
Z = {};for ii=1:size(X,2); Z = [ Z , X(:,ii) ] ; end
arrayfun(f,Z{:},'UniformOutput',false)

The third and fourth arguments appear to be needed because f is vector valued.