Arrayfun - problem with input array

I've found this kind of problem:

clear all;
a=[3,7,9,5,11,2];
b=[1,2,3,4,5,6];
l=[1,0,0,0,0,0];
f=@(x,z,y) x*l(y);
l=arrayfun(f,a,l,b);

which gives

l=[3,0,0,0,0,0]

on the contrary if i want to refere to "l" through the input value "z" in this way:

a=[3,7,9,5,11,2];
b=[1,2,3,4,5,6];
l=[1,0,0,0,0,0];
f=@(x,z,y) x*z(y);
l=arrayfun(f,a,l,b);

it gives

Index exceeds matrix dimensions.

Error in @(x,z,y)x*z(y)

why? is there a way of passing the array itself l=arrayfun(.....,l) and changing its value simultaneously?

Answer 1

[NISARGA G K]

Hi Damiano,

I understand that you would like to change the value of array passed to 'arrayfun'.

B = arrayfun(func,A1,...,An) applies func to the elements of the arrays A1,...,An, so that B(i) = func(A1(i),...,An(i))

Since arrayfun access is element wise 'z' passed to function is scalar and hence z(y) is not possible. The following code would help you to change the value of array passed directly

a={[3,7,9,5,11,2]};
b={[1,2,3,4,5,6]};
l={[1,0,0,0,0,0]};
f=@(x,z,y) x.*z(y);
l=cellfun(f,a,l,b,'UniformOutput',0);