Round

proc _round {num index} {
  # Procedure to round numerical results to any decimal or whole number.
  # The decimal or whole number digit is indicated using an index.
  # Index 0 is the nearest integer.
  # Decimals are indicated by positive indicies:  1 or the first decimal, 2 for the second, etc.
  # Whole numbers are indicated by negative indicies:  -1 for nearest 10th, -2 for the nearest hundreth, etc.
  # Example:
  #
  #     Number:  9  9 9 . 9 9 9
  #     Index:  -2 -1 0   1 2 3
  #
  # Index  1 = 0.x
  # Index  2 = 0.0x
  # Index  3 = 0.00x
  # Index  0 = x
  # Index -1 = x0
  # Index -2 = x00
  # Index -3 = x000
 
  set multiplier [expr pow(10,$index)]
  return [expr (round(($num * $multiplier)) / $multiplier)]
}