How can I add all the differents additions to one scalar output?

Write a function called summit that takes three vectors of the

same length as input arguments (the function does not have to check the format

of the input) and returns a scalar as output. If it is called like this,

a = summit (x,y,z)

then

a = x(1)^2 + y(1)*z(1) + x(2)^2 + y(2)*z(2) + . . . +

x(N)^2 + y(N)*z(N),

where N equals the length of x. This function must not use an array operation,

and it must not use the function sum. Instead, it must instead use a forloop.

[KSSV]

Okay what is question for us?

[Steven Lord]

This sounds like a homework assignment. If it is, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the MATLAB Onramp tutorial (https://www.mathworks.com/support/learn-with-matlab-tutorials.html) to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

[Marta Gonzalez]

I wrote this code:

function v=vector_algebra(a,b,c)

N=length(a)

for n=1:N

v=a(n)^2+b(n)*c(n)

end

end

So it gives me a vector with the different values that it gets at each index, but how can I get a scalar that is the result of the sum of those values without using the sum function ?

Answer 1

[KSSV]

x = rand(3,1) ; 
y = rand(3,1) ; 
z = rand(3,1) ; 
N = length(x) ; 
v = 0 ;
for i = 1:N
  v = v+x(i)^2+y(i)*z(i) ; 
end

[Marta Gonzalez]

Thanks, I didn't see that, it was such a stupid error

[KSSV]

Thanks is accepting the answer.