Reference documentation for deal.II version 9.2.0
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#include <deal.II/differentiation/ad/ad_drivers.h>
Public Member Functions | |
Taping | |
bool | is_recording () const |
Types< ADNumberType >::tape_index | active_tape_index () const |
bool | is_registered_tape (const typename Types< ADNumberType >::tape_index tape_index) const |
bool | keep_independent_values () const |
void | set_tape_buffer_sizes (const typename Types< ADNumberType >::tape_buffer_sizes obufsize=64 *1024 *1024, const typename Types< ADNumberType >::tape_buffer_sizes lbufsize=64 *1024 *1024, const typename Types< ADNumberType >::tape_buffer_sizes vbufsize=64 *1024 *1024, const typename Types< ADNumberType >::tape_buffer_sizes tbufsize=64 *1024 *1024) |
void | start_taping (const typename Types< ADNumberType >::tape_index tape_index, const bool keep_independent_values) |
void | stop_taping (const typename Types< ADNumberType >::tape_index active_tape_index, const bool write_tapes_to_file) |
std::vector< typename Types< ADNumberType >::tape_index > | get_registered_tape_indices () const |
void | activate_tape (const typename Types< ADNumberType >::tape_index tape_index) |
bool | requires_retaping (const typename Types< ADNumberType >::tape_index tape_index) const |
bool | last_action_requires_retaping () const |
void | remove_tape (const typename Types< ADNumberType >::tape_index tape_index) |
void | reset (const bool clear_registered_tapes) |
void | print (std::ostream &stream) const |
void | print_tape_stats (const typename Types< ADNumberType >::tape_index tape_index, std::ostream &stream) const |
Drivers for scalar functions (one dependent variable) | |
ScalarType | value (const typename Types< ADNumberType >::tape_index active_tape_index, const std::vector< ScalarType > &independent_variables) const |
void | gradient (const typename Types< ADNumberType >::tape_index active_tape_index, const std::vector< ScalarType > &independent_variables, Vector< ScalarType > &gradient) const |
void | hessian (const typename Types< ADNumberType >::tape_index active_tape_index, const std::vector< ScalarType > &independent_variables, FullMatrix< ScalarType > &hessian) const |
Drivers for vector functions (multiple dependent variables) | |
void | values (const typename Types< ADNumberType >::tape_index active_tape_index, const unsigned int n_dependent_variables, const std::vector< ScalarType > &independent_variables, Vector< ScalarType > &values) const |
void | jacobian (const typename Types< ADNumberType >::tape_index active_tape_index, const unsigned int n_dependent_variables, const std::vector< ScalarType > &independent_variables, FullMatrix< ScalarType > &jacobian) const |
A prototype driver class for taped auto-differentiable numbers.
It is intended that this class be specialized for the valid combinations of auto-differentiable numbers and output scalar number types.
ADNumberType | A type corresponding to a supported auto-differentiable number. |
ScalarType | A real or complex floating point number type that is the scalar value type used for input to, and output from, operations performed with auto-differentiable numbers. |
T | An arbitrary type resulting from the application of the SFINAE idiom to selectively specialize this class. |
Definition at line 150 of file ad_drivers.h.
bool Differentiation::AD::TapedDrivers< ADNumberType >::is_recording |
Return whether or not this class is tracking calculations performed with its marked independent variables.
Definition at line 58 of file ad_drivers.cc.
Types< ADNumberType >::tape_index Differentiation::AD::TapedDrivers< ADNumberType >::active_tape_index |
Return the tape number which is currently activated for recording or reading.
Definition at line 67 of file ad_drivers.cc.
bool Differentiation::AD::TapedDrivers< ADNumberType >::is_registered_tape | ( | const typename Types< ADNumberType >::tape_index | tape_index | ) | const |
Return whether or not a tape number has already been used or registered.
Definition at line 76 of file ad_drivers.cc.
bool Differentiation::AD::TapedDrivers< ADNumberType >::keep_independent_values |
Return whether or not the numerical values of all independent variables are recorded in the tape buffer.
Definition at line 86 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::set_tape_buffer_sizes | ( | const typename Types< ADNumberType >::tape_buffer_sizes | obufsize = 64 * 1024 * 1024 , |
const typename Types< ADNumberType >::tape_buffer_sizes | lbufsize = 64 * 1024 * 1024 , |
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const typename Types< ADNumberType >::tape_buffer_sizes | vbufsize = 64 * 1024 * 1024 , |
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const typename Types< ADNumberType >::tape_buffer_sizes | tbufsize = 64 * 1024 * 1024 |
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) |
Set the buffer sizes for the next active tape.
This function must be called before start_recording_operations() for it to have any influence on the memory allocated to the next recorded tape.
[in] | obufsize | ADOL-C operations buffer size |
[in] | lbufsize | ADOL-C locations buffer size |
[in] | vbufsize | ADOL-C value buffer size |
[in] | tbufsize | ADOL-C Taylor buffer size |
Definition at line 95 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::start_taping | ( | const typename Types< ADNumberType >::tape_index | tape_index, |
const bool | keep_independent_values | ||
) |
Enable the recording mode for a given tape.
[in] | tape_index | The index of the tape to be written. |
[in] | keep_independent_values | Determines whether the numerical values of all independent variables are recorded in the tape buffer. |
Definition at line 107 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::stop_taping | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const bool | write_tapes_to_file | ||
) |
Disable the recording mode for a given tape.
[in] | active_tape_index | The index of the (currently active) tape to be finalized and potentially written to file. |
[in] | write_tapes_to_file | A flag that specified whether the tape should be written to file or kept in memory. |
Definition at line 117 of file ad_drivers.cc.
std::vector< typename Types< ADNumberType >::tape_index > Differentiation::AD::TapedDrivers< ADNumberType >::get_registered_tape_indices |
Return a list of registered tape indices.
Definition at line 127 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::activate_tape | ( | const typename Types< ADNumberType >::tape_index | tape_index | ) |
Select a tape to record to or read from.
This function activates a tape, but depending on whether read_mode
is set, the tape is either taken as previously written to (and put into read-only mode), or cleared for (re-)taping.
[in] | tape_index | The index of the tape to be written to/read from. |
Definition at line 137 of file ad_drivers.cc.
bool Differentiation::AD::TapedDrivers< ADNumberType >::requires_retaping | ( | const typename Types< ADNumberType >::tape_index | tape_index | ) | const |
Return a flag that, when true
, indicates that the retaping of the dependent function for the chosen tape_index
is necessary for a reliable computation to be performed. This may be necessary if a sign comparison within branched operations yields different results to those computed at the original tape evaluation point.
This issue, known as "branch switching", can be clarified by means of a trivial, contrived example:
During taping, the conditional statement may be either true
or false
, and the result (with its sensitivities) returned by this function. The AD library doesn't just record the parse tree of the operations applied on the branch chosen at the time to taping, but also checks that the condition continues to be satisfied. For some other evaluation of the tape (i.e. for some different inputs x
and y
), the other branch of the conditional check may be chosen. The result of following this code path has not been recorded on the tape, and therefore cannot be evaluated. In such a case, the underlying AD library will be able to tell you that it is necessary to re-record the tape at the new evaluation point in order to resolve the new code branch. This function can be used to find out whether this is so.
Definition at line 146 of file ad_drivers.cc.
bool Differentiation::AD::TapedDrivers< ADNumberType >::last_action_requires_retaping |
Return a flag that, when true
, indicates that the retaping of the dependent function is necessary for a reliable computation to be performed on the currently active tape. This may be necessary if a sign comparison within branched operations yields different results to those computed at the original tape evaluation point.
This issue, known as "branch switching", can be clarified by means of a trivial, contrived example:
During taping, the conditional statement may be either true
or false
, and the result (with its sensitivities) returned by this function. The AD library doesn't just record the parse tree of the operations applied on the branch chosen at the time to taping, but also checks that the condition continues to be satisfied. For some other evaluation of the tape (i.e. for some different inputs x
and y
), the other branch of the conditional check may be chosen. The result of following this code path has not been recorded on the tape, and therefore cannot be evaluated. In such a case, the underlying AD library will be able to tell you that it is necessary to re-record the tape at the new evaluation point in order to resolve the new code branch. This function can be used to find out whether this is so.
Definition at line 156 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::remove_tape | ( | const typename Types< ADNumberType >::tape_index | tape_index | ) |
Completely erases the tape with the given tape_index
.
Definition at line 166 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::reset | ( | const bool | clear_registered_tapes | ) |
Reset the state of the class.
Definition at line 175 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::print | ( | std::ostream & | stream | ) | const |
Print the status of all queryable data. Exactly what is printed and its format depends on the ad_type
, as is determined by the ADNumberTypeCode
template parameter.
[in] | stream | The output stream to which the values are to be written. |
Definition at line 183 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::print_tape_stats | ( | const typename Types< ADNumberType >::tape_index | tape_index, |
std::ostream & | stream | ||
) | const |
Print the statistics regarding the usage of the tapes.
[in] | tape_index | The index of the tape to get the statistics of. |
[out] | stream | The output stream to which the values are to be written. |
Definition at line 191 of file ad_drivers.cc.
TapedDrivers< ADNumberType, float, typename std::enable_if< ADNumberTraits< ADNumberType >::type_code==NumberTypes::adolc_taped >::type >::scalar_type Differentiation::AD::TapedDrivers< ADNumberType >::value | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const std::vector< ScalarType > & | independent_variables | ||
) | const |
Compute the value of the scalar field.
[in] | active_tape_index | The index of the tape on which the dependent function is recorded. |
[in] | independent_variables | The scalar values of the independent variables whose sensitivities were tracked. |
Definition at line 201 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::gradient | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const std::vector< ScalarType > & | independent_variables, | ||
Vector< ScalarType > & | gradient | ||
) | const |
Compute the gradient of the scalar field with respect to all independent variables.
[in] | active_tape_index | The index of the tape on which the dependent function is recorded. |
[in] | independent_variables | The scalar values of the independent variables whose sensitivities were tracked. |
[out] | gradient | The values of the dependent function's gradients. It is expected that this vector be of the correct size (with length n_independent_variables ). |
Definition at line 212 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::hessian | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const std::vector< ScalarType > & | independent_variables, | ||
FullMatrix< ScalarType > & | hessian | ||
) | const |
Compute the Hessian of the scalar field with respect to all independent variables.
[in] | active_tape_index | The index of the tape on which the dependent function is recorded. |
[in] | independent_variables | The scalar values of the independent variables whose sensitivities were tracked. |
[out] | hessian | The values of the dependent function's Hessian. It is expected that this matrix be of the correct size (with dimensions n_independent_variables \(\times\)n_independent_variables ). |
Definition at line 223 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::values | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const unsigned int | n_dependent_variables, | ||
const std::vector< ScalarType > & | independent_variables, | ||
Vector< ScalarType > & | values | ||
) | const |
Compute the values of the vector field.
[in] | active_tape_index | The index of the tape on which the dependent function is recorded. |
[in] | n_dependent_variables | The number of dependent variables. |
[in] | independent_variables | The scalar values of the independent variables whose sensitivities were tracked. |
[out] | values | The component values of the dependent functions. It is expected that this vector be of the correct size (with length n_dependent_variables ). |
Definition at line 234 of file ad_drivers.cc.
void Differentiation::AD::TapedDrivers< ADNumberType >::jacobian | ( | const typename Types< ADNumberType >::tape_index | active_tape_index, |
const unsigned int | n_dependent_variables, | ||
const std::vector< ScalarType > & | independent_variables, | ||
FullMatrix< ScalarType > & | jacobian | ||
) | const |
Compute the Jacobian of the vector field.
The Jacobian of a vector field is in essence the gradient of each dependent variable with respect to all independent variables. This operation is therefore analogous to the gradient() operation performed on a collection of scalar valued fields.
[in] | active_tape_index | The index of the tape on which the dependent function is recorded. |
[in] | n_dependent_variables | The number of dependent variables. |
[in] | independent_variables | The scalar values of the independent variables whose sensitivities were tracked. |
[out] | jacobian | The component values of the dependent functions' Jacobian. It is expected that this matrix be of the correct size (with dimensions n_dependent_variables \(\times\)n_independent_variables ). |
Definition at line 246 of file ad_drivers.cc.