"The function fun must accept two arrays of the same size and return an array of corresponding values. It must perform element-wise operations."
What does your function do?
fun = @(x,y) 1-exp(-0.01*norm(x-y));
x = 1:10;
y = x+1;
z = fun(x, y)
Is z the same size as x and y? I think something closer to what you want is:
fun = @(x,y) 1-exp(-0.01*abs(x-y));
x = 1:10;
y = x+1;
z = fun(x, y)
