overview of functions provided#
// namespaces namespace conf; // typedefs typedef float spc_; typedef double rpc_; typedef int ipc_; // structs struct psls_control_type; struct psls_inform_type; struct psls_time_type; // global functions void psls_initialize( void **data, struct psls_control_type* control, ipc_ *status ); void psls_read_specfile( struct psls_control_type* control, const char specfile[] ); void psls_import( struct psls_control_type* control, void **data, ipc_ *status, ipc_ n, const char type[], ipc_ ne, const ipc_ row[], const ipc_ col[], const ipc_ ptr[] ); void psls_reset_control( struct psls_control_type* control, void **data, ipc_ *status ); void psls_form_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[] ); void psls_form_subset_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[], ipc_ n_sub, const ipc_ sub[] ); void psls_update_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[], ipc_ n_del, const ipc_ del[] ); void psls_apply_preconditioner(void **data, ipc_ *status, ipc_ n, rpc_ sol[]); void psls_information(void **data, struct psls_inform_type* inform, ipc_ *status); void psls_terminate( void **data, struct psls_control_type* control, struct psls_inform_type* inform );
typedefs#
typedef float spc_
spc_
is real single precision
typedef double rpc_
rpc_
is the real working precision used, but may be changed to float
by
defining the preprocessor variable REAL_32
or (if supported) to
__real128
using the variable REAL_128
.
typedef int ipc_
ipc_
is the default integer word length used, but may be changed to
int64_t
by defining the preprocessor variable INTEGER_64
.
function and structure names#
The function and structure names described below are appropriate for the
default real working precision (double
) and integer word length
(int32_t
). To use the functions and structures with different precisions
and integer word lengths, an additional suffix must be added to their names
(and the arguments set accordingly). The appropriate suffices are:
_s
for single precision (float
) reals and
standard 32-bit (int32_t
) integers;
_q
for quadruple precision (__real128
) reals (if supported) and
standard 32-bit (int32_t
) integers;
_64
for standard precision (double
) reals and
64-bit (int64_t
) integers;
_s_64
for single precision (float
) reals and
64-bit (int64_t
) integers; and
_q_64
for quadruple precision (__real128
) reals (if supported) and
64-bit (int64_t
) integers.
Thus a call to psls_initialize
below will instead be
void psls_initialize_s_64(void **data, struct psls_control_type_s_64* control, int64_t *status)
if single precision (float
) reals and 64-bit (int64_t
) integers are
required. Thus it is possible to call functions for this package
with more that one precision and/or integer word length at same time. An
example is provided for the package expo
,
and the obvious modifications apply equally here.
function calls#
void psls_initialize( void **data, struct psls_control_type* control, ipc_ *status )
Set default control values and initialize private data
Parameters:
data |
holds private internal data |
control |
is a struct containing control information (see psls_control_type) |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are (currently):
|
void psls_read_specfile( struct psls_control_type* control, const char specfile[] )
Read the content of a specification file, and assign values associated with given keywords to the corresponding control parameters. An in-depth discussion of specification files is available, and a detailed list of keywords with associated default values is provided in $GALAHAD/src/psls/PSLS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/psls.pdf for a list of how these keywords relate to the components of the control structure.
Parameters:
control |
is a struct containing control information (see psls_control_type) |
specfile |
is a character string containing the name of the specification file |
void psls_import( struct psls_control_type* control, void **data, ipc_ *status, ipc_ n, const char type[], ipc_ ne, const ipc_ row[], const ipc_ col[], const ipc_ ptr[] )
Import structural matrix data into internal storage prior to solution.
Parameters:
control |
is a struct whose members provide control paramters for the remaining prcedures (see psls_control_type) |
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
n |
is a scalar variable of type ipc_, that holds the number of rows in the symmetric matrix \(A\). |
type |
is a one-dimensional array of type char that specifies the symmetric storage scheme used for the matrix \(A\). It should be one of ‘coordinate’, ‘sparse_by_rows’ or ‘dense’; lower or upper case variants are allowed. |
ne |
is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of \(A\) in the sparse co-ordinate storage scheme. It need not be set for any of the other schemes. |
row |
is a one-dimensional array of size ne and type ipc_, that holds the row indices of the lower triangular part of \(A\) in the sparse co-ordinate storage scheme. It need not be set for any of the other three schemes, and in this case can be NULL. |
col |
is a one-dimensional array of size ne and type ipc_, that holds the column indices of the lower triangular part of \(A\) in either the sparse co-ordinate, or the sparse row-wise storage scheme. It need not be set when the dense storage scheme is used, and in this case can be NULL. |
ptr |
is a one-dimensional array of size n+1 and type ipc_, that holds the starting position of each row of the lower triangular part of \(A\), as well as the total number of entries, in the sparse row-wise storage scheme. It need not be set when the other schemes are used, and in this case can be NULL. |
void psls_reset_control( struct psls_control_type* control, void **data, ipc_ *status )
Reset control parameters after import if required.
Parameters:
control |
is a struct whose members provide control paramters for the remaining prcedures (see psls_control_type) |
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
void psls_form_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[] )
Form and factorize a preconditioner \(P\) of the matrix \(A\).
Parameters:
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
ne |
is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of the symmetric matrix \(A\). |
val |
is a one-dimensional array of size ne and type rpc_, that holds the values of the entries of the lower triangular part of the symmetric matrix \(A\) in any of the supported storage schemes. |
void psls_form_subset_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[], ipc_ n_sub, const ipc_ sub[] )
Form and factorize a \(P\) preconditioner of a symmetric submatrix of the matrix \(A\).
Parameters:
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
ne |
is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of the symmetric matrix \(A\). |
val |
is a one-dimensional array of size ne and type rpc_, that holds the values of the entries of the lower triangular part of the symmetric matrix \(A\) in any of the supported storage schemes. |
n_sub |
is a scalar variable of type ipc_, that holds the number of rows (and columns) of the required submatrix of \(A\). |
sub |
is a one-dimensional array of size n_sub and type ipc_, that holds the indices of the rows of required submatrix. |
void psls_update_preconditioner( void **data, ipc_ *status, ipc_ ne, const rpc_ val[], ipc_ n_del, const ipc_ del[] )
Update the preconditioner \(P\) when rows (amd columns) are removed.
Parameters:
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
ne |
is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of the symmetric matrix \(A\). |
val |
is a one-dimensional array of size ne and type rpc_, that holds the values of the entries of the lower triangular part of the symmetric matrix \(A\) in any of the supported storage schemes. |
n_del |
is a scalar variable of type ipc_, that holds the number of rows (and columns) of (sub) matrix that are to be deleted. |
del |
is a one-dimensional array of size n_fix and type ipc_, that holds the indices of the rows that are to be deleted. |
void psls_apply_preconditioner(void **data, ipc_ *status, ipc_ n, rpc_ sol[])
Solve the linear system \(Px=b\).
Parameters:
data |
holds private internal data |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are:
|
n |
is a scalar variable of type ipc_, that holds the number of entries in the vectors \(b\) and \(x\). |
sol |
is a one-dimensional array of size n and type double. On entry, it must hold the vector \(b\). On a successful exit, its contains the solution \(x\). Any component corresponding to rows/columns not in the initial subset recorded by psls_form_subset_preconditioner, or in those subsequently deleted by psls_update_preconditioner, will not be altered. |
void psls_information(void **data, struct psls_inform_type* inform, ipc_ *status)
Provide output information
Parameters:
data |
holds private internal data |
inform |
is a struct containing output information (see psls_inform_type) |
status |
is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are (currently):
|
void psls_terminate( void **data, struct psls_control_type* control, struct psls_inform_type* inform )
Deallocate all internal private storage
Parameters:
data |
holds private internal data |
control |
is a struct containing control information (see psls_control_type) |
inform |
is a struct containing output information (see psls_inform_type) |