\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)
size_order¶
View page sourceNumber Taylor Coefficient Orders Currently Stored¶
Syntax¶
s = f . size_order ()
See Also¶
Purpose¶
Determine the number of Taylor coefficient orders, per variable,direction, currently calculated and stored in the ADFun object f . See the discussion under Constructor , Forward , and capacity_order for a description of when this value can change.
f¶
The object f has prototype
const ADFun< Base > f
s¶
The result s has prototype
size_ts
and is the number of Taylor coefficient orders, per variable,direction in the AD operation sequence, currently calculated and stored in the ADFun object f .
Constructor¶
Directly after the fun_construct syntax
ADFun< Base > f ( x , y )
the value of s returned by size_order is one.
This is because
there is an implicit call to Forward that computes
the zero order Taylor coefficients during this constructor.
Forward¶
After a call to Forward with the syntax
f .
Forward( q , x_q )
the value of s returned by size_order
would be \(q + 1\).
The call to Forward above
uses the lower order Taylor coefficients to compute and store
the q-th order Taylor coefficients for all
the variables in the operation sequence corresponding to f .
Thus there are \(q + 1\) (order zero through q )
Taylor coefficients per variable,direction.
(You can determine the number of variables in the operation sequence
using the size_var function.)
capacity_order¶
If the number of Taylor coefficient orders currently stored in f is less than or equal c , a call to capacity_order with the syntax
f .
capacity_order( c )
does not affect the value s returned by size_order .
Otherwise,
the value s returned by size_order
is equal to c
(only Taylor coefficients of order zero through \(c-1\)
have been retained).
Example¶
The file forward.cpp contains an example and test of this operation.