Elapsed Time

proc _elapsedTime { start end } {
  # Procedure to measure the time elapsed.
  # Arguments are two points in time measured in seconds.
  # Use as follows:
  #   set start [clock seconds]
  #   set end   [clock seconds]
  #   _elapsed_time $start $end
 
  set total_seconds [expr $end - $start]
  set _hours [expr int($total_seconds/3600)]
  set _minutes [expr int(($total_seconds % 3600)/60)]
  set _seconds [expr int(($total_seconds % 60))]
  if {$_hours == 1} {set htxt hour} else {set htxt hours}
  if {$_minutes == 1} {set mtxt minute} else {set mtxt minutes}
  if {$_seconds == 1} {set stxt second} else {set stxt seconds}
  if {$_hours == 0} {
    if {$_minutes == 0} {
      return "$_seconds $stxt"
    } else {
      return "$_minutes $mtxt $_seconds $stxt"
    }
  } else {
    return "$_hours $htxt $_minutes $mtxt $_seconds $stxt"
  }
}