CppAD: A C++ Algorithmic Differentiation Package
20171217


inline 
Zero order forward mode implementation of op = StvvOp.
The C++ source code corresponding to this operation is
v[x] = y
where v is a VecAD<Base> vector, x is an AD<Base> object, and y is AD<Base> or Base objects. We define the index corresponding to v[x] by
i_v_x = index_by_ind[ arg[0] + i_vec ]
where i_vec is defined under the heading arg[1] below:
Base  base type for the operator; i.e., this operation was recorded using AD<Base> and computations by this routine are done using type Base. 
i_z  is the index corresponding to the previous variable on the tape (only used for error checking). 
arg  arg[0] is the offset of this VecAD vector relative to the beginning of the isvar_by_ind and index_by_ind arrays. arg[1] If this is a StppOp or StpvOp operation (if x is a parameter), i_vec is defined by i_vec = arg[1]If this is a StvpOp or StvvOp operation (if x is a variable), i_vec is defined by i_vec = floor( taylor[ arg[1] * cap_order + 0 ] )where floor(c) is the greatest integer less that or equal c. arg[2] index corresponding to the third operand for this operator; i.e. the index corresponding to y. 
num_par  is the total number of parameters on the tape (only used for error checking). 
cap_order  number of columns in the matrix containing the Taylor coefficients. 
taylor  In StvpOp and StvvOp cases, <taylor[ arg[1] * cap_order + 0 ] is used to compute the index in the definition of i_vec above. 
isvar_by_ind  If y is a varable (StpvOp and StvvOp cases), isvar_by_ind[ arg[0] + i_vec ] is set to true. Otherwise y is a paraemter (StppOp and StvpOp cases) and isvar_by_ind[ arg[0] + i_vec ] is set to false. 
index_by_ind  index_by_ind[ arg[0]  1 ] is the number of elements in the user vector containing this element. The value index_by_ind[ arg[0] + i_vec] is set equal to arg[2]. 
i_vec < index_by_ind[ arg[0]  1 ]
Note that, if x is a parameter, the corresponding vector index and it does not change. In this case, the error above should be detected during tape recording.Definition at line 306 of file store_op.hpp.
Referenced by forward0sweep(), and forward1sweep().