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Function data types for parameters and arguments. More...
#include <FunctionTraits.h>
Public Types | |
typedef T | Type |
Actual template type. | |
typedef T | BaseType |
Template base type. | |
typedef T | NumericType |
Numeric type of template. | |
typedef T | ParamType |
Type for parameters. | |
typedef T | ArgType |
Type for arguments. | |
typedef AutoDiff< T > | DiffType |
Default type for differentiation. | |
Static Public Member Functions | |
static const T & | getValue (const T &in) |
Get the value. | |
static void | setValue (T &out, const T &val, const uInt, const uInt) |
Set a value (and possible derivative). |
Function data types for parameters and arguments.
Internal
A trait is a characteristic feature. FunctionTraits defines relationships between the data types of result, parameters and arguments of function objects.
This templated class contains a number of typedefs that describe the relationship between different numeric data types used for the calculation of Function
and the function parameter and arguments.
Its main use is to optimize the speed of the calculation of function values and derivatives in the case of AutoDiff
use and manual calculation of derivatives, by allowing the data type of the the arguments and/or parameters to be plain numeric in cases where the derivatives wrt these are not needed. To enable this, the following definitions are used for the use of the Function template. Bear in mind that the Function operator is defined as result = f<T>(x; parameters)
.
AutoDiff<T>
indicates the calculation (either automatic or with specialized implementations) of the result with a T
function value for T
arg, and AutoDiff<T>
parameters. AutoDiffA
calculate form AutoDiff<T>
arguments and parameters (note that either could be simple values with zero derivatives) AutoDiffX<T>
: calculate only with respect to the arguments the derivatives, by using T
parameters The following types are defined:
Type
BaseType
Double
for AutoDiff<Double>
) NumericType
Double
for AutoDiff<AutoDiff<Double> >
ParamType
ArgType
DiffType
AutoDiff<Double>
for AutoDiff<Double>
) getValue()
AutoDiff
setValue()
AutoDiff
The specializations are done in such a way that higher order derivatives (e.g. AutoDiff<AutoDiff<Double> >
) are catered for.
Note that the class names in the following definitions are extended with some individual id (like _PA
): do not use them in programming, they are only necessary for the cxx2html
interpreter)
This class is implemented as a number of specializations for the following data types.
See the Function class code.
To keep the Function class single templated
AutoDiff*
classes if and when needed Definition at line 139 of file FunctionTraits.h.
typedef T casa::FunctionTraits< T >::ArgType |
Type for arguments.
Definition at line 150 of file FunctionTraits.h.
typedef T casa::FunctionTraits< T >::BaseType |
Template base type.
Definition at line 144 of file FunctionTraits.h.
typedef AutoDiff<T> casa::FunctionTraits< T >::DiffType |
Default type for differentiation.
Definition at line 152 of file FunctionTraits.h.
typedef T casa::FunctionTraits< T >::NumericType |
Numeric type of template.
Definition at line 146 of file FunctionTraits.h.
typedef T casa::FunctionTraits< T >::ParamType |
Type for parameters.
Definition at line 148 of file FunctionTraits.h.
typedef T casa::FunctionTraits< T >::Type |
Actual template type.
Definition at line 142 of file FunctionTraits.h.
static const T& casa::FunctionTraits< T >::getValue | ( | const T & | in | ) | [inline, static] |
Get the value.
Definition at line 154 of file FunctionTraits.h.
static void casa::FunctionTraits< T >::setValue | ( | T & | out, | |
const T & | val, | |||
const | uInt, | |||
const | uInt | |||
) | [inline, static] |
Set a value (and possible derivative).
Definition at line 156 of file FunctionTraits.h.