How do I use a sum function in a for loop?

x = [1, 23,43, 72, 87, 56, 98, 33]

Find:

1) Use a for loop to sum the elements in the vector

2) Repeat the previous problem, this time using a while loop

3) Use a for loop to create a vector of the squares of the numbers 1 through 5.

4) Use a while loop to create a vector of the squares of the numbers 1 through 5.

5) Use the primes function to create a list of all the primes below 100. Now use a for loop to multiply adjacent values together.

[Geoff Hayes]

Milanna - rather than posting your homework question, why not post what you have tried to solve this problem? See loop control structures for details on how to construct for and while loops.

[Andrew Newell]

How do I get help on homework questions on MATLAB Answers?

Answer 1

[Saurabh]

1. 
total = 0;  % Initialize the accumulator variable
for i = 1:length(x)
    total = total + x(i);
end

2. 
total = 0;
i = 1;
while i <= length(x)
    total = total + x(i);
    i = i + 1;
end

3.
squares = zeros(1, 5);
for i = 1:5
    squares(i) = i^2;
end

4.
i = 1;
square = zeros(1, 5);
while i <= 5
    squares(i) = i^2;
    i = i + 1;
end

5.
primes_list = primes(100)
for i = 1:length(x) - 1
    prime_list(i) = prime_list(i) * prime_list(i + 1);
end

%actually fifth question is not very clear, what the output structure, can
%you provide a little more detail about this.