Matlab: store input variables for arrayfun

Hi all,

I have the following function:

function [value_final] = myvalue(fd)

value_final = (fs + (fd.*(th.^2)));

end

Values for th and fs are constant, but for fd I use

fd = linspace(0,50,20);
th=5;
fs=8.5;
B = arrayfun(@myvalue,fd);

How can I create a matrix with in the first column each input value for 'fd' and in the second column the corresponding value for 'value_final' for each iteration? Later I want to include a range of values for 'fs' as well, so it would be nice to know which combination yields which value.

Thanks!

Answer 1

[Star Strider]

First, rewrite the function to include the additional parameters:

function [value_final] = myvalue(fd,fs,th)
value_final = (fs + (fd.*(th.^2)));
end

then pass them to it using an anonymous function within arrayfun:

fd = linspace(0,50,20);
th=5;
fs=8.5;
B = arrayfun(@(fd)myvalue(fd,fs,th),fd(:));
Out = [fd(:) B]

Since ‘myvalue’ is an external function, not an anonymous function, you have to pass the additional parameters to it. It will not pick them up from your workspace.

See if this does what you want.

[yoni verhaegen]

Thanks! What should I change to this code if I want to include a range of values for 'fs' = linspace(0,50,20) as well?

[Star Strider]

As always, my pleasure!

This will do what you want:

fd = linspace(0,50,20);
th=5;
fs = linspace(0,50,20);
B = arrayfun(@(fd)myvalue(fd,fs,th),fd(:), 'UniformOutput',false);
Bmtx = cell2mat(B);
Out = [fd(:) Bmtx];

Note that for this to work as you want it to, ‘fs’ must remain a row vector (as it is currently defined in this code). The ‘(:)’ in ‘fd(:)’ forces it to be a column vector. (The arrayfun call will still work if you force ‘fs’ to also be a column vector. The concatenation to create the ‘Out’ matrix will not, since the row sizes will not be the same.)