How do I sum the elements in a vector up to a specific value?

I need to sum the numbers in an array up to the value 10. So with a function input of v=[2,3,2,2,1,3,1,10,3], I would not include 10 or any values after it in the sum. Below I have the function I am working with, I am currently getting an output of 18 instead of 14

function [prize]=sumPrize(v)

prize=0;

for i=1:length(v)<10

prize = prize + v(i);

end

end

[the cyclist]

See my answer, but an explanation of why yours does not work is probably helpful.

Your loop does not do what you think it does. The line

for i=1:length(v)<10

is evaluated as follows:

1. Calculate the length of the vector v, which is 9
2. Create the vector 1:length(v), which is the vector [1 2 3 4 5 6 7 8 9]
3. Test whether each element of that vector is less than 10. Since they all are, the result is [1 1 1 1 1 1 1 1 1]
4. Loop over that vector

So, your for loop is equivalent to

for i = [1 1 1 1 1 1 1 1 1]
    prize = prize + v(i);
end

which means you are just summing the 1st element of v, 9 times. That's why you get 18.

Answer 1

[the cyclist]

Here is one way:

v = [2,3,2,2,1,3,1,10,3];
prize = sum(v(1:find(v==10,1)-1))

prize = 14