Odometry not returning values

Programming Support
10

I am pasting your code here wrapped in the [code] ... [/code] tags:

#include "vex.h"
#include "math.h"
#define PI 3.14159265
using namespace vex;
//////////////////////////////////////////////////////////////////////////
//Odometry Task///////////////////////////////////////////////////////////
//Initial values
double initial_Dir;
double initial_x;
double initial_y;
//X and Y coordinates
double x;
double y;
//Current values
double Dir;
double l_dist;
double r_dist;
double b_dist;
//Previous values
double prev_Dir;
double prev_L;
double prev_R;
double prev_B;
//Combo values
double Dir_diff = Dir - prev_Dir;
double r_diff = r_dist - prev_R;
double l_diff = l_dist - prev_L;
double b_diff = b_dist - prev_B;
double rR; //translation value
double bR;
double l_dfc = 5; //left track wheel distance from center
double r_dfc = 5; //right track wheel distance from center
double b_dfc = 5; //back track wheel dist from center
double twc = 10.2102; //track wheel circumference - (3.25 * 3.14159)
int OdometryTask()
{
  while(1)
  {
      l_dist = LTrack.position(turns) * twc;
      r_dist = RTrack.position(turns) * twc;
      b_dist = BTrack.position(turns) * twc;
      Dir = (((l_dist - r_dist) / (l_dfc + r_dfc)) * (180 / 3.14159)) + initial_Dir;
      rR = (r_diff / Dir_diff) + r_dfc;
      bR = (b_diff / Dir_diff) + b_dfc;
      x = (2 * sin(Dir / 2)) * bR;
      y = (2 * sin(Dir / 2)) * rR;
      Brain.Screen.printAt(175, 60, "Gyro %.3f", Dir); //Output to brain screen
      Brain.Screen.printAt(175, 120, "x %.1f", x);
      Brain.Screen.printAt(175, 180, "y %.1f", y);
      Controller1.Screen.setCursor(3, 1);
      Controller1.Screen.print("Gyro %.2f", Dir);
      printf("Gyro %.4f", Dir);
      printf(" X_Pos %.2f", x);
      printf(" Y_Pos %.2f\n", y);
      vex::task::sleep(15);
      prev_Dir = Dir;
      prev_L = l_dist;
      prev_R = r_dist;
      prev_B = b_dist;
   }
 return(0);
}
vex::task o(OdometryTask); //Start Odometry Task

Is this your entire code?
Do you have main() function?
What are the LTrack, RTrack, and BTrack sensors?

My guess would be that, first, you need to have variables like Dir_diff initialized to some non-zero values to avoid division on the first iteration and, second, ensure that rotation sensors are properly setup and given enough time to initialize.

See here: