Sum of array as an others array value


Hi everyone, im new and this is my first question here.
I’m wondering why this is not possible:

If i Type:

A=[1.0, 2.0, 3.0, 4.0, 5.0];

and then


i get the error Message:

error in method definition: function Base.sum must be explicitly imported to be extended

Why is this ?



its Float64 like the elements of B?



does not work , but now with the error mesasage:

syntax: "A[1:3]" is not a valid function argument name



You can’t extend a Base method without importing it first. sum(A) = B[1] is a method definition, this is entirely different from just typing sum(A), because = is an assignment operator.

sum(A[1:3])=B[1] is invalid syntax.



Perhaps it would be useful if you explain what you’re trying to do, or what you expect to happen?

Also, to show code please use backticks (`) or triple-backticks(```) (I took the liberty of editing your post).


It is not clear from your question what you really want to do or what is the expected behavior that you assumed. Perhaps you mean to do this?

A = [1.0, 2.0, 3.0, 4.0, 5.0]
B = zeros(5)

B[1] = sum(A)
B[1] = sum(A[1:3]) 


Seif_Shebl, you are right, that is what i really wanted t do…and it works fine.
what a stupid mistake of mine…
Thanks a lot for the answers to everybody.