Public Member Functions | Public Attributes

bio_expression::Derive Class Reference

Class generating the analytical derivative of an expression. More...

Inheritance diagram for bio_expression::Derive:
bio_expression::Expression

List of all members.

Public Member Functions

def __init__
def getExpression

Public Attributes

 function
 variable
 operatorIndex

Detailed Description

Class generating the analytical derivative of an expression.

This class generates the expression for

\[ \frac{\partial f(x)}{\partial x} \]

The computation of derivatives is usually not necessary for estimation, as Biogeme automatically generates the analytical derivatives of the log likelihood function. It is particularly usuful for simulation, to compute the elasticities of complex models. Example: The computation of the elasticity of a model prob with respect to the variable TRAIN_TT, say, is obtained as follows, whatever the model defined by prob:

 elasticity = Derive(prob,'TRAIN_TT') * TRAIN_TT / prob

Constructor & Destructor Documentation

def bio_expression::Derive::__init__ (   self,
  term,
  v 
)
Parameters:
termany valid bio_expression to derive
vthe variable

Member Function Documentation

def bio_expression::Derive::getExpression (   self )
Returns:
Return the string representation of the current expression

Reimplemented from bio_expression::Expression.


Member Data Documentation

Reimplemented from bio_expression::Expression.


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