CODEWITHSUNDEEP
matlab
annie
annie

Reputation: 11

multiply functions in matlab

I am trying to solve following functions 

k=2;
G(1)=292000.0;
G(2)=262000.0;
Ld(1)=0.00396;
Ld(2)=0.0344;
deps=10;
aa=3.7;
ms=0.0;

 for i=1:k
    ms=@(x) ms+(G(i)/Ld(i))*exp(-x./Ld(i))

 end

f=@(x) (exp(x.*2*deps)-exp(-x.*deps))/((aa-3)+(2*exp(x.*deps)+exp(-2*x.*deps)))
g=@(x) ms(x).*f(x)
g(1);

but I receive this error "Undefined function or method 'plus' for input arguments of type 'function_handle'."

hope somebody can help me out..Thanks

Upvotes: 1

Views: 7221

Answers (2)

Jonas
Jonas

Reputation: 74940

The problematic lines are:

ms=0.0;

 for i=1:k
    ms=@(x) ms+(G(i)/Ld(i))*exp(-x./Ld(i))

 end

Inside the loop, you treat ms as both a function handle as well as a number, which won't work.

Although recursive definition of a function handle is most likely not the best way to go, it is - to my surprise - possible. Thus, you can write:

ms = @(x)0; %# initialize 'ms' to nothing
for i=1:k
    ms = @(x) ms(x) +(G(i)/Ld(i))*exp(-x./Ld(i));
end

Upvotes: 1

gnovice
gnovice

Reputation: 125874

As Jonas already pointed out, the problem is that you treat ms interchangeably as a numeric value and a function handle, which you can't do.

You actually don't need the for loop to generate the anonymous function ms. You can create it in one line using the function SUM like so:

ms = @(x) sum((G./Ld).*exp(-x./Ld));

This will give you a final result of g(1) = 0.0199;.

Upvotes: 2

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