forming a function handles in matrix

I want to form a set of function handles in a row matrix.

i wrote script like below.

w = 2;

Nr = 20

nr = @(phi)zeros(1, Nr);

wr = @(phi)zeros(1, Nr);

for n = 1:Nr

for i = 1:w

Awr = 50*(cos(i*2)-cos(i*9));

nr(1, n) = @(phi)nr(1, n)+Awr*cos(i*1.7);

end

wr(1, n) = @(phi)nr(1, n)

end

Iam getting the below error

Nonscalar arrays of function handles are not allowed; use cell arrays instead.

how to rectify this??

Answer 1

[Steven Lord]

MATLAB used to allow nonscalar arrays of function handles, but that functionality was removed probably 10 to 15 years ago. As the error message suggested, store your function handles in a cell array instead.

[Bathala Teja]

Can you show me how to do that?

thanks in advance

[Steven Lord]

f = {@sin, @cos, @(t) t.^2}

f = 1×3 cell array
    {@sin}    {@cos}    {@(t)t.^2}

y = f{3}(1:10) % returns the first 10 perfect squares

y = 1×10

1 4 9 16 25 36 49 64 81 100

fh = f{2} % returns the function handle @cos

fh = function_handle with value:
    @cos

[Bathala Teja]

sorry i did mistake in giving my script

this is my script, now iam expecting array(contains Nr = 20 elements) of function handles as output

w = 2;
Nr = 20
nr = @(phi)zeros(1, Nr);
wr = @(phi)zeros(1, Nr);
  for n = 1:Nr
        for i = 1:w
            Awr = 50*(cos(i*2)-cos(i*9));
            nr(1, n) = @(phi)nr(1, n)+Awr*cos(i*(phi+2*n));
        end
      wr(1, n) = @(phi)nr(1, n);
  end
  NR = @(phi)nr(phi)+(3*56/2)

[Steven Lord]

Creating an array of function handles is not allowed. It will not work.

Creating a cell array containing function handles is allowed.

f = cell(1, 3);
for k = 1:3
    f{k} = @(x) x.^k + k*x;
end
% Use the elements of f by indexing then passing the input
y = f{2}(1:10) % Evaluate the function handle corresponding to k = 2 at x = 1:10

y = 1×10

3 8 15 24 35 48 63 80 99 120

check = (1:10).^2 + 2*(1:10) % Manual check, will be the same as y

check = 1×10

3 8 15 24 35 48 63 80 99 120

[Bathala Teja]

Script is fine.

If i want to do f{1}*f{2}, it is giving error.

How to do this operation.

[Stephen23]

@Bathala Teja: function handles cannot be multiplied (or have any numeric operation applied to them). But you can certainly evaluate the function handles (just as Steven Lord showed) and multiply their outputs:

f{1}(3)*f{2}(3)
%   ^^^     ^^^ Evaluate!

[Bathala Teja]

See this

Here i performed multiflication of two function handles and after that i integrated total function.

What is the difference in between this one and above one?

m = 10;
nAi = @(phi)zeros(1, 1);
for i=1:2:m
    Ams = (2/(pi*i))*sin(pi*i/3)*(1+(2*cos(pi*i/9))); 
    nAi = @(phi)nAi(phi)+Ams*cos(2*i*phi);
end
nA = @(phi)50+nAi(phi) 

nA = function_handle with value:
    @(phi)50+nAi(phi)

wA = @(phi)nAi(phi)

wA = function_handle with value:
    @(phi)nAi(phi)

nBi = @(phi)zeros(1, 1);
for i=1:2:m
    Ams = (2/(pi*i))*sin(pi*i/3)*(1+2*cos(pi*i/9));
    nBi = @(phi)nBi(phi)+Ams*cos(2*i*(phi-((2*pi/3)/4)));
end
nB = @(phi)50+nBi(phi) 

nB = function_handle with value:
    @(phi)50+nBi(phi)

wB = @(phi)nBi(phi)

wB = function_handle with value:
    @(phi)nBi(phi)

Lab = integral(@(phi)(nA(phi).*wB(phi)), 0, 2*pi)

Lab = 3.9695