code: def eqToEq2000(ra_deg, dec_deg, eq):
      
      ra_rad = math.radians(ra_deg)
      dec_rad = math.radians(dec_deg)
  
      x = math.cos(dec_rad) * math.cos(ra_rad)
      y = math.cos(dec_rad) * math.sin(ra_rad)
      z = math.sin(dec_rad)
  
      p11, p12, p13, p21, p22, p23, p31, p32, p33 = trans_coeff(eq, x, y, z)
  
      x0 = p11 * x + p21 * y + p31 * z
      y0 = p12 * x + p22 * y + p32 * z
      z0 = p13 * x + p23 * y + p33 * z
  
      new_dec = math.asin(z0)
      if x0 == 0.0:
          new_ra = math.pi / 2.0
      else:
          new_ra = math.atan(y0 / x0)
  
      if ((y0 * math.cos(new_dec) > 0.0 and x0 * math.cos(new_dec) <= 0.0) or
              (y0 * math.cos(new_dec) <= 0.0 and x0 * math.cos(new_dec) < 0.0)):
          new_ra += math.pi
  
      elif new_ra < 0.0:
          new_ra += 2.0 * math.pi
  
      #new_ra = new_ra * 12.0 * 3600.0 / math.pi
      new_ra_deg = new_ra * 12.0 / math.pi * 15.0
  
      #new_dec = new_dec * 180.0 * 3600.0 / math.pi
      new_dec_deg = new_dec * 180.0 / math.pi
  
      return (new_ra_deg, new_dec_deg)
docs: Convert Eq to Eq 2000.