text: # Copyright (c) 2016, Joseph R. Peterson
  # All rights reserved.
  # 
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions are met:
  # 
  # * Redistributions of source code must retain the above copyright notice, this
  #   list of conditions and the following disclaimer.
  # 
  # * Redistributions in binary form must reproduce the above copyright notice,
  #   this list of conditions and the following disclaimer in the documentation
  #   and/or other materials provided with the distribution.
  # 
  # * Neither the name of PerfectBru nor the names of its
  #   contributors may be used to endorse or promote products derived from
  #   this software without specific prior written permission.
  # 
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  # AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  # DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  # SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  import numbers
  
  class Variable(object):
  	""" A variable that includes a mean and uncertainty region.
  	
  	Attributes:
  		value (:obj:`float`): the mean of the variable
  		bounds (:obj:`float` or :obj:`tuple`): Bounds as either a single number or a 2 tuple
  
  	"""
  
  	def __init__(self, value, bounds):
  		""" Create a variable.
  
  		Args:
  			value (:obj:`float`): The value of the `Variable`
  			bounds (:obj:`float` or :obj:`tuple`): Bounds as either a single number or a 2 tuple for lower and higher 
  
  		"""
  		self.value = value
  		self.bounds = bounds
  		if not isinstance(value, float):
  			raise ValueError("'value' must be a float")
  		if not isinstance(bounds,float) and not isinstance(bounds,tuple):
  			raise ValueError("'bounds' must be a float or a 2 tuple")
  		if isinstance(bounds,tuple):
  			if len(bounds) != 2:
  				raise ValueError("bounds tuple must be of length 2")
  
  	def __repr__(self):
  		thestr = "%f"%(self.value)
  		if isinstance(bounds,tuple):
  			thestr += "±[%f,%f]"%(self.bounds[0],self.bounds[1])
  		else:
  			thestr += "±%f"%self.bounds
  		return thestr
  
  
  