Matrix with function handle: how to evaluate for a vector

Hello everyone,

Is there a way, if given a certain matrix with some function handles of n variables, to evaluate it with of vector giving values to those n variables?

Here's my exemple to make it clearer:

I have this matrix that is given has an input for a fucntion I'm coding:

J = @(x,y,z)[2*exp(2*x),0,-cos(x);-1,1,0;0,2*z,1]

And I have the vector:

X=[1;1;1] (I also tried writing it as X=[1,1,1])

And I would like to evaluate J with X in my code, but nothing I tried seems to work. Both J(X) and feval(J,X) return errors. Basically I would like to have the matrix J(1,1,1) without having to write it that way because I would like to directly take my matrix input to evaluate it with the vector input. Is there a way to do it?

Answer 1

[Matt J]

Write J so that it has single argument syntax,

 J = @(xyz) [2*exp(2*xyz(1)),0,-cos(xyz(1));-1,1,0;0,2*xyz(3),1];
 
 X=[1;1;1];
 J(X)

ans = 3×3

14.7781 0 -0.5403 -1.0000 1.0000 0 0 2.0000 1.0000

[Pascale Robillard]

Thank you! :)

[Matt J]

You're welcome, but please Accept-click the preferred answer your problem.

Answer 2

[Walter Roberson]

J3 = @(V)J(V(1),V(2),V(3))

However if you happen to be generating the J function using the Symbolic toolbox then see the Vars option for matlabFunction, in particular 'vars', {[x, y, z]} would cause the generated function to expect a row vector of values.

[Pascale Robillard]

Thank you!