array of function handle

I have to convert a code written using syms, to a code with function handle. (my prof doesn't want me to use syms)

how can I select the element of the array?

I write a simpler code

A=@(x)[sin(x), cos(x);1, -1];
B=@(x)[sin(x);cos(x)];
C=@(x) A(x)*B(x); % this is an array of 2 element
D=@(x) C(first element) - C(second element)

Answer 1

[Walter Roberson]

First = @(x) x(1);
Second = @(x) x(2);
D = @(x) First(C(x)) - Second(C(x));

However, this will execute C twice. More efficient would be

FirstMinusSecond = @(x) x(1) - x(2);
D = @(x) FirstMinusSecond(C(x))

[Simo]

ok it works thanks, but if I want to plot D?

---------------------

l=linspace(0,3*pi);

plot(l,D(l))

--------------------

error:

--------------------

Error using vertcat

Dimensions of arrays being concatenated are not consistent.

Error in Untitled3 (line 3)

A=@(x)[sin(x), cos(x);1, -1];

Error in Untitled3 (line 5)

C=@(x) A(x)*B(x); % this is an array of 2 element

Error in Untitled3 (line 7)

D = @(x) FirstMinusSecond(C(x));

Error in Untitled3 (line 10)

plot(l,D(l))

[Walter Roberson]

Your A and B and C are only valid if x is a scalar, and your D would be unlikely to return the value you want if x is not a scalar. If you want to plot then instead of

plot(l,D(l))

do

y = arrayfun(D, l);
plot(l, y)