Hi guys. I am trying to modeling financial markets. Looking for google, I have found this global variable: long idum In the main(), it is defined as idum = -9132434 or in many other ways. I am using the following libraries: #include <stdio.h> #include <stdlib.h> #include <math.h> #include <string.h> #include "ran2.h" Could you please tell me what this variable is for? Many thanks.