Source code for bxa.sherpa.cachedmodel

#!/usr/bin/env python
# -*- coding: utf-8 -*- 
from __future__ import print_function

"""
BXA (Bayesian X-ray Analysis) for Sherpa

Copyright: Johannes Buchner (C) 2013-2016
"""

import os

if 'MAKESPHINXDOC' not in os.environ:
	from sherpa.models import ArithmeticModel, CompositeModel
	from sherpa.models.parameter import Parameter
else:
	ArithmeticModel = object
	CompositeModel = list
	Parameter = None


class VariableCachedModel(CompositeModel, ArithmeticModel):
	"""Wrapper that caches the most recent model call."""
	def __init__(self, othermodel):
		"""*othermodel* can be any sherpa model"""
		self.othermodel = othermodel
		self.cache = None
		self.lastp = None
		print('calling CompositeModel...')
		CompositeModel.__init__(self, name='cached(%s)' % othermodel.name, parts=(othermodel,))
	
	def calc(self, p, left, right, *args, **kwargs):
		if self.cache is None or self.lastp != p:
			self.cache = self.othermodel.calc(p, left, right, *args, **kwargs)
			self.lastp = p
		return self.cache

	def startup(self):
		self.othermodel.startup()
		CompositeModel.startup(self)
	
	def teardown(self):
		self.othermodel.teardown()
		CompositeModel.teardown(self)

	def guess(self, dep, *args, **kwargs):
		self.othermodel.guess(dep, *args, **kwargs)
		CompositeModel.guess(self, dep, *args, **kwargs)

class CachedModel(CompositeModel, ArithmeticModel):
	"""Wrapper that caches the first model call forever."""
	def __init__(self, othermodel):
		"""*othermodel* can be any sherpa model"""
		self.othermodel = othermodel
		self.cache = None
		self.relnorm = Parameter('cache', 'relnorm', 1, 0, 1e10, 0, 1e10)
		CompositeModel.__init__(self, name='cached(%s)' % othermodel.name, parts=(othermodel,))
	
	def calc(self, *args, **kwargs):
		if self.cache is None:
			print('   computing cached model ... ')
			self.cache = self.othermodel.calc(*args, **kwargs)
		return self.cache * self.relnorm.val

	def startup(self):
		self.othermodel.startup()
		CompositeModel.startup(self)
	
	def teardown(self):
		self.othermodel.teardown()
		CompositeModel.teardown(self)

	def guess(self, dep, *args, **kwargs):
		self.othermodel.guess(dep, *args, **kwargs)
		CompositeModel.guess(self, dep, *args, **kwargs)