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Topic: Prime (Read 766 times) |
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rgovostes
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Prime
« on: Feb 3rd, 2004, 1:32am » |
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These give a visualization of prime numbers without having to check each number for being prime. The first displaces the results in a grid, with dark squares representing prime numbers, and grey ones representing composite (non-prime) numbers. The second is a bit faster, and instead just use a single pixel for each number.
Neither has been optimized much. I could check to see if the number being tested is greater than the square root of the maximum number, and if so stop, but I do not think this would speed it up much if at all.
Code:// Prime v1, Feb 02 '04
// by Ryan Govostes
int cols = 23; // Prime
int rows = 30;
int sizex = 20;
int sizey = 20;
int n = 1;
int[] isPrime = new int[(cols * rows) + 1];
void setup() {
size((cols * sizex) + 1, (rows * sizey) + 1);
stroke(50);
isPrime[1] = 2;
}
void loop() {
int v = n;
while(v <= (cols * rows) && isPrime[v] > 0) { v ++; }
if (v <= (cols * rows)) {
isPrime[v] = 2;
for(int x = (v * 2); x <= (cols * rows); x += v) {
isPrime[x] = 1;
}
n = v;
}
background(255);
for(int i = 0; i < (cols * rows); i ++) {
if (isPrime[i + 1] == 0) { noFill(); } // nil
else if (isPrime[i + 1] == 1) { fill(200); } // not prime
else if (isPrime[i + 1] == 2) { fill(100); } // prime
rect((i % cols) * sizex, floor(i / cols) * sizey, sizex, sizey);
}
} |
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Code:// Prime Pixels v1, Feb 02 '04
// by Ryan Govostes
int n = 1;
color nil, prime, composite;
void setup() {
nil = color(255, 255, 255);
prime = color(100, 100, 100);
composite = color(200, 200, 200);
size(200, 200);
background(nil);
pixels[0] = prime;
}
void loop() {
int z;
while(n < (width * height) && pixels[n - 1] != nil) { n ++; }
if (n < (width * height)) {
pixels[n - 1] = prime;
//z = 0;
for(int x = (n * 2); x < (width * height); x += n) {
pixels[x - 1] = composite;
// z ++;
}
//println("Discovered " + z + " composite numbers.");
}
} |
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| « Last Edit: Feb 5th, 2004, 12:53am by rgovostes » |
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