Iterate through vector a using a for loop and create a new

Question

Question: Use either a for or while loop.

Part 1: Iterate through vector A using a for loop and create a new vector B containing logical values. The new vector should contain true for positive values and false for all other values.

Part 2: Same as part A excpet use a while loop

Part 3: Iterate through a logical array N using a for loop and return a new vector M containing the value 2 wherever an element of N is true and a -1 where N is false

Part 4: Iterate through an array z using a while loop. Replace every element with number 3 until you reach a value larger than 50. Leave the rest unchanged.

Comment the code, determine the form of the output depended on the coefficients being input.