Atomic Function Reverse Dependency Calculation

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Syntax

ok = afun.rev_depend(

    parameter_x, type_x, depend_x, depend_y

)

Prototype


template <class Base>
bool atomic_three<Base>::rev_depend(
    const vector<Base>&         parameter_x ,
    const vector<ad_type_enum>& type_x      ,
    vector<bool>&               depend_x    ,
    const vector<bool>&         depend_y    )

Dependency Analysis
This calculation is sometimes referred to as a reverse dependency analysis.

Implementation
This function must be defined if afun is used to define an ADFun object f , and f.optimize() is used.

Base
See Base .

parameter_x
See parameter_x .

type_x
See type_x .

depend_x
This vector has size equal to the number of arguments for this atomic function; i.e. n=ax.size() . The input values of the elements of depend_x are not specified (must not matter). Upon return, for

$j = 0 , \ldots , n-1$ , depend_x[j] is true if the values of interest depend on the value of ax[j] in the corresponding afun(ax, ay) call.

Optimize
Parameters and variables, that the values of interest do not depend on, may get removed by optimization . The corresponding values in parameter_x , and taylor_x (after optimization has removed them) are not specified.

depend_y
This vector has size equal to the number of results for this atomic function; i.e. m=ay.size() . For

$i = 0 , \ldots , m-1$ , depend_y[i] is true if the values of interest depend on the value of ay[i] in the corresponding afun(ax, ay) call.

ok
If this calculation succeeded, ok is true. Otherwise, it is false.

Contents

atomic_three_rev_depend.cpp

Atomic Functions Reverse Dependency Analysis: Example and Test

Example
The following is an example of a atomic function rev_depend definition: atomic_three_rev_depend.cpp .

Input File: include/cppad/core/atomic/three/rev_depend.hpp