element by element sum with two arrays

I basicly have to arrays A1 and B1 and would like to do this

sum(over i)((A1(i)-a*B1(i)-b)^2)

so i tried using this

sum((A1-a*B1-b).^2)

but that does not do it element by element

any hints?

a and b are constants

[Kye Taylor]

Can you provide concrete values for a,b,A1,B1 as @Thomas does above? Can you also give/describe the output that you're looking for?

Answer 1

[Thomas]

Is this how you want it..

A1=[1:4];
B1=[5:8];
a=2;
b=2;

c=(A1-a.*(B1-b)).^2  % just to show the element wise subtract and square

sum(c)

[Adam Parry]

I don't think that is quite right.

C = (A1-(a*B1)-b).^2

but will it still give me the correct element wise sum?

[Ryan]

Thomas did misplace a parentheses.

What is in your original post should do exactly what you asked it to do. By using "sum()" you are summing up all of the components of the vector thus resulting in a singular result. If that is not what you'd like, then you should try adding more detail and writing out your problem statement as clear as possible so we can try to help.