How can I use a vector inside an @fun?

Hello everyone,

I want to define a function like "fun = @(x) sin(a*x)" where "a" is a vector of n dimention.

Do you have any idea?

Thank you for your support.

Greetings.

Answer 1

[Artemio Soto Breceda]

I might not be understanding your question properly, but it looks like your code works just fine. Here is an example:

a = linspace(0,2*pi,1000); % Create a vector of dimension N = 1000 with values increasing
                           % linearly from 0 to 2*pi
fun = @(x) sin(a*x);       % Define your function
plot(a, fun(1));           % plot 1 period of the sine wave (from 0 to 2*pi);
hold
plot(a, fun(2));           % x = 2
plot(a, fun(4));           % x = 4

I made a a 1000 elements vector, then used your exact code to define fun, and used the new function with three different inputs. Works perfectly as you wrote it.

[Walter Roberson]

I agree, in the context provided, using a vector or matrix inside an anonymous function is not a problem.

The kinds of problems that can arise:

• the majority of the time you should use the vector operations such as .* and .^ and ./ instead of * and ^ and /
• fzero and the minimizers such as fmincon cannot work with vectors or arrays being returned: gamultiobj is the only minimizer that can work with vectors being returned
• integral() can only deal with vectors or arrays being returned if you use the 'arrayvalued' option
• integral2() cannot deal with vectors or arrays being returned
• if you are using arrayfun() or cellfun() or stuctfun() then you need to use 'uniform', 0 to return non-scalars

[Carlos Zúñiga]

Thank you!

Answer 2

[Joe Vinciguerra]

Assign 'a' first, then assign 'fun'. In your application I don't believe you can do it the other way around.

[Carlos Zúñiga]

Thank you!