hwrf.numerics.partial_ordering Class Reference

Sorts a pre-determined list of objects, placing unknown items at a specified location. More...

Detailed Description

Sorts a pre-determined list of objects, placing unknown items at a specified location.

This class is a drop-in replacement for cmp in sorting routines. It represents a partial ordering of objects by specifying the order of a known subset of those objects, and inserting all unknown objects in a specified location in the that list (at the end, by default) in an order determined by cmp(a,b). Example:

p=partial_ordering([3,2,1]) # list is ordered as [3,2,1] with
                            #  everything else after that

sorted([0,1,2,3,6,4,5],p)  # = [3, 2, 1, 0, 4, 5, 6]
p(1,-99)  # = -1, so -99 goes after 1 since -99 is not
          #   in the partial ordering
p(1,3)    # = 1, so 3 goes before 1 since 3 is before 1
          #   in the partial ordering
p(5,10)   # = -1 since cmp(5,10)=-1

Definition at line 21 of file numerics.py.

Inheritance diagram for hwrf.numerics.partial_ordering:

Public Member Functions
def	__init__
	partial_ordering constructor. More...
def	__call__ (self, a, b)
	Determine the ordering of a and b. More...

Public Attributes
	order
	Internal ordering information.
	backupcmp
	Backup comparison function for tiebreaking.
	unordered
	Unordered element index.

Constructor & Destructor Documentation

def hwrf.numerics.partial_ordering.__init__	(		self,
			ordering,
			unordered = None,
			backupcmp = cmp
	)

partial_ordering constructor.

Creates a partial ordering. The subset that is ordered is specified by the ordered iterable "ordered" while the index at which to place unordered values is optionally specified by "unordered", which can be anything that can be cmp()'ed to an int. If "unordered" is missing, then all objects not in "ordered" will be placed at the end of any list. To place at the beginning of the list, give unordered=0. To insert between the first and second elements, specify 1, between second and third elements: specify unordered=2, and so on. Specify another tiebreaker "cmp" function with "backupcmp" (default: cmp).

Parameters

ordering	the ordering of known objects
unordered	Optional: where to put other objects
backupcmp	Tiebreaker comparison function.

Definition at line 42 of file numerics.py.

Member Function Documentation

def hwrf.numerics.partial_ordering.__call__	(		self,
			a,
			b
	)

Determine the ordering of a and b.

Parameters

a,b	the objects to order

Returns

-1 if b>a, 1 if b<a, 0 if b and a belong in the same index.

Definition at line 86 of file numerics.py.

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The documentation for this class was generated from the following file:

• /mnt/pan2/projects/hwrfv3/Samuel.Trahan/trunk/ush/hwrf/numerics.py