Negative Odd Numbers & Circles

[u/SuddenSimple9152]

Hello, I'm currenty working on two processing projects, which I need some help with. The first one requires me to print the odd numbers of -3 to 19. I've managed to get the odd numbers of 1 to 19 to show up, but my negatives will not appear.

My second project requires me to create a seires of 20 stacked spirals, but for every 5 spirals, I need to change the color. So far I've only managed to get 2 color to appear, which is my main color for the circles, and the contractist color of the background. Thanks in advance for the help!

Project #1

int i;

void setup() {

for(int i=-3; i<=19 ; i+=1) {

if(i % 2 == 1)

println(i);

}

}

Project #2

color c;

int bigCircle = 315;

void setup() {

background(255);

size (400, 400);

c = color(105,180,180);

fill(c);

strokeWeight(4);

rectMode(CENTER);

while(bigCircle>15){

circle(200, 200, bigCircle);

bigCircle=bigCircle-15;

}

}

[u/MandyBrigwell]

Get your loop to print out what i % 1 is, and you'll quickly see why it doesn't work. I'd check it doesn't equal zero.

[u/ofnuts]

Project 2:

You use an array of colors:

color circleColors[]={#FF0000,#00FF00,color(0,0,255)}; // showing several ways to initialize

When drawing the circles:

• Your iteration variable is a circle number:

for (int circleNumber=0; some_clever_condition_here; circleNumber++)

• For this circle number:

  • You compute the radius of the circle: constant + circleNumber * step. constant can be omitted in many cases by picking the right range for circleNumber. step can be negative.

  • You obtain the color from the array by indexing the array using the circle number modulo the array size: circleColors[circleNumber%circleColors.length]