#===========================================================================
#
# Duration
#
#===========================================================================
"""Duration module."""
#===========================================================================
# Place all imports after here.
#
#
# Place all imports before here.
#===========================================================================
#===========================================================================
class Duration:
"""Class Duration in development.
"""
allowed = [ "ET", "UTC" ]
#-----------------------------------------------------------------------
def __init__( self, frame, seconds ):
"""Create a new Duration object.
= ERROR CONDITIONS
- If the input frame is not in the allowed list, an error is thrown.
= INPUT VARIABLES
- frame The frame of the duration. Must be 'ET' or 'UTC'
- seconds The number of seconds in the Duration.
"""
if frame not in self.allowed:
msg = "Input frame '%s' is not one of the supported frames of %s" \
% ( frame, str( self.allowed ) )
raise ValueError( msg )
self._frame = frame
self._seconds = seconds
#-----------------------------------------------------------------------
def frame( self ):
"""Return the frame the duration is in."""
return self._frame
#-----------------------------------------------------------------------
def __abs__( self ):
"""Return the absolute value of the duration."""
return Duration( self._frame, abs( self._seconds ) )
#-----------------------------------------------------------------------
def __neg__( self ):
"""Return the negative value of this Duration."""
return Duration( self._frame, -self._seconds )
#-----------------------------------------------------------------------
def seconds( self ):
"""Return the number of seconds in the Duration."""
return self._seconds
#-----------------------------------------------------------------------
def __nonzero__( self ):
"""Compare two Durations.
= INPUT VARIABLES
- rhs The Duration to compare against.
= RETURN VALUE
- Returns -1 if self < rhs, 0 if self == rhs, +1 if self > rhs.
"""
return self._seconds != 0
#-----------------------------------------------------------------------
def __cmp__( self, rhs ):
"""Compare two Durations.
= ERROR CONDITIONS
- If the input rhs is not in the same frame, an error is thrown.
= INPUT VARIABLES
- rhs The Duration to compare against.
= RETURN VALUE
- Returns -1 if self < rhs, 0 if self == rhs, +1 if self > rhs.
"""
self.checkSameFrame( rhs, "compare" )
return cmp( self._seconds, rhs._seconds )
#-----------------------------------------------------------------------
def __add__( self, rhs ):
"""Add two Durations.
= ERROR CONDITIONS
- If the input rhs is not in the same frame, an error is thrown.
= INPUT VARIABLES
- rhs The Duration to add.
= RETURN VALUE
- Returns the sum of ourselves and the input Duration.
"""
# Delay-load due to circular dependencies.
import mplTest.units as U
if isinstance( rhs, U.Epoch ):
return rhs + self
self.checkSameFrame( rhs, "add" )
return Duration( self._frame, self._seconds + rhs._seconds )
#-----------------------------------------------------------------------
def __sub__( self, rhs ):
"""Subtract two Durations.
= ERROR CONDITIONS
- If the input rhs is not in the same frame, an error is thrown.
= INPUT VARIABLES
- rhs The Duration to subtract.
= RETURN VALUE
- Returns the difference of ourselves and the input Duration.
"""
self.checkSameFrame( rhs, "sub" )
return Duration( self._frame, self._seconds - rhs._seconds )
#-----------------------------------------------------------------------
def __mul__( self, rhs ):
"""Scale a UnitDbl by a value.
= INPUT VARIABLES
- rhs The scalar to multiply by.
= RETURN VALUE
- Returns the scaled Duration.
"""
return Duration( self._frame, self._seconds * float( rhs ) )
#-----------------------------------------------------------------------
def __rmul__( self, lhs ):
"""Scale a Duration by a value.
= INPUT VARIABLES
- lhs The scalar to multiply by.
= RETURN VALUE
- Returns the scaled Duration.
"""
return Duration( self._frame, self._seconds * float( lhs ) )
#-----------------------------------------------------------------------
def __div__( self, rhs ):
"""Divide a Duration by a value.
= INPUT VARIABLES
- rhs The scalar to divide by.
= RETURN VALUE
- Returns the scaled Duration.
"""
return Duration( self._frame, self._seconds / float( rhs ) )
#-----------------------------------------------------------------------
def __rdiv__( self, rhs ):
"""Divide a Duration by a value.
= INPUT VARIABLES
- rhs The scalar to divide by.
= RETURN VALUE
- Returns the scaled Duration.
"""
return Duration( self._frame, float( rhs ) / self._seconds )
#-----------------------------------------------------------------------
def __str__( self ):
"""Print the Duration."""
return "%g %s" % ( self._seconds, self._frame )
#-----------------------------------------------------------------------
def __repr__( self ):
"""Print the Duration."""
return "Duration( '%s', %g )" % ( self._frame, self._seconds )
#-----------------------------------------------------------------------
def checkSameFrame( self, rhs, func ):
"""Check to see if frames are the same.
= ERROR CONDITIONS
- If the frame of the rhs Duration is not the same as our frame,
an error is thrown.
= INPUT VARIABLES
- rhs The Duration to check for the same frame
- func The name of the function doing the check.
"""
if self._frame != rhs._frame:
msg = "Cannot %s Duration's with different frames.\n" \
"LHS: %s\n" \
"RHS: %s" % ( func, self._frame, rhs._frame )
raise ValueError( msg )
#===========================================================================
