Questions regarding code in the tutorials (IG.duration and for loop)

[Higemoto]

Hi,
I'm currently training on IGeo and reached the last tutorial of this page http://igeo.jp/tutorial/36.html (updating Agents using vectors).

I was wondering why do we need a for loop in the following :
import processing.opengl.;
import igeo.;
void setup(){
size(480, 360, IG.GL);
IG.duration(250);
int num = 40;
float inc = 2PI/num;
for(int i=0; i < num; i++){
new MyAgent(IG.v(40cos(iinc), 40sin(iinc), 0),
IG.v(5cos((i+6)*inc), sin((i+6)*inc), 0));
}
}

the IG.duration is setting up how many times the action is done, what is the role of that For Loop and the variable "int num = 40" ?

Does it mean there will be 40 initial instances starting at 40 different positions as the i is implemented in the vectors ?

Thanks in advance,
Gari,