I'm having a problem getting this lookup table to work.

//Create A Look Up Table
void setup(){
}
void draw(){
 float t = cosine(0);
 println(t);
}
float[] costable = new float[360];
for( int i = 0; i<360; i++) {
 float ang = (360-i)/180;
 ang *= PI;
 costable[i] = cos(ang);
 }
float cosine(int theta) {
 return costable[theta];

float sine(float theta) {
 return costable[theta + 90]
}