Running through a randomly generated array and doing calculations

Here's the problem statement: "Consider an array x of randomly generated positive and negative integers. Write a script that performs the following iteration: starting with 0 it goes through the entries of x, adds them to the total if they are positive and multiplies them by the total if they are negative."

The array x has been provided. It's a 1x20 matrix named HW1Rand

Here's the code I've got so far:

HW1_6a = 0; %initialization
for ii = HW1Rand(1,1:20)
    if ii>0
        HW_6a == HW_6a + ii
    else
        HW_6a == HW_6a * ii
    end
end

However I keep getting an error. Please help!

[Ian]

note: there are no zeros in the array HW1Rand!

Answer 1

[Mischa Kim]

Ian, what is HW1Rand(1,1:20), in other words, how is the function/matrix defined? Also, for assignments in MATLAB you'd use a simple =. The == is a relational operator.

Finally, you are initializing HW1_6a but use HW_6a in the calculations.

HW_6a = 0;                % initialization
for ii = HW1Rand(1,1:20)  % assuming HW1Rand is properly defined
    if ii>0
        HW_6a = HW_6a + ii
    else
        HW_6a = HW_6a * ii
    end
end