overview of functions provided#

// namespaces

namespace conf;

// typedefs

typedef float spc_;
typedef double rpc_;
typedef int ipc_;

// structs

struct sbls_control_type;
struct sbls_inform_type;
struct sbls_time_type;

// global functions

void sbls_initialize(
    void **data,
    struct sbls_control_type* control,
    ipc_ *status
);

void sbls_read_specfile(
    struct sbls_control_type* control,
    const char specfile[]
);

void sbls_import(
    struct sbls_control_type* control,
    void **data,
    ipc_ *status,
    ipc_ n,
    ipc_ m,
    const char H_type[],
    ipc_ H_ne,
    const ipc_ H_row[],
    const ipc_ H_col[],
    const ipc_ H_ptr[],
    const char A_type[],
    ipc_ A_ne,
    const ipc_ A_row[],
    const ipc_ A_col[],
    const ipc_ A_ptr[],
    const char C_type[],
    ipc_ C_ne,
    const ipc_ C_row[],
    const ipc_ C_col[],
    const ipc_ C_ptr[]
);

void sbls_reset_control(
    struct sbls_control_type* control,
    void **data,
    ipc_ *status
);

void sbls_factorize_matrix(
    void **data,
    ipc_ *status,
    ipc_ n,
    ipc_ h_ne,
    const rpc_ H_val[],
    ipc_ a_ne,
    const rpc_ A_val[],
    ipc_ c_ne,
    const rpc_ C_val[],
    const rpc_ D[]
);

void sbls_solve_system(void **data, ipc_ *status, ipc_ n, ipc_ m, rpc_ sol[]);
void sbls_information(void **data, struct sbls_inform_type* inform, ipc_ *status);

void sbls_terminate(
    void **data,
    struct sbls_control_type* control,
    struct sbls_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 sbls_initialize below will instead be

void sbls_initialize_s_64(void **data, struct sbls_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 sbls_initialize(
    void **data,
    struct sbls_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 sbls_control_type)

status

is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are (currently):

0
The initialization was successful.

void sbls_read_specfile(
    struct sbls_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/sbls/SBLS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/sbls.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 sbls_control_type)
specfile	is a character string containing the name of the specification file

void sbls_import(
    struct sbls_control_type* control,
    void **data,
    ipc_ *status,
    ipc_ n,
    ipc_ m,
    const char H_type[],
    ipc_ H_ne,
    const ipc_ H_row[],
    const ipc_ H_col[],
    const ipc_ H_ptr[],
    const char A_type[],
    ipc_ A_ne,
    const ipc_ A_row[],
    const ipc_ A_col[],
    const ipc_ A_ptr[],
    const char C_type[],
    ipc_ C_ne,
    const ipc_ C_row[],
    const ipc_ C_col[],
    const ipc_ C_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 sbls_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: 0 The import was successful. -1 An allocation error occurred. A message indicating the offending array is written on unit control.error, and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -2 A deallocation error occurred. A message indicating the offending array is written on unit control.error and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -3 The restrictions n > 0 or m > 0 or requirement that a type contains its relevant string ‘dense’, ‘coordinate’, ‘sparse_by_rows’, ‘diagonal’, ‘scaled_identity’, ‘identity’, ‘zero’ or ‘none’ has been violated.
n	is a scalar variable of type ipc_, that holds the number of rows in the symmetric matrix $H$.
m	is a scalar variable of type ipc_, that holds the number of rows in the symmetric matrix $C$.
H_type	is a one-dimensional array of type char that specifies the symmetric storage scheme used for the matrix $H$. It should be one of ‘coordinate’, ‘sparse_by_rows’, ‘dense’, ‘diagonal’, ‘scaled_identity’, ‘identity’, ‘zero’ or ‘none’, the latter pair if $H=0$; lower or upper case variants are allowed.
H_ne	is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of $H$ in the sparse co-ordinate storage scheme. It need not be set for any of the other schemes.
H_row	is a one-dimensional array of size H_ne and type ipc_, that holds the row indices of the lower triangular part of $H$ 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.
H_col	is a one-dimensional array of size H_ne and type ipc_, that holds the column indices of the lower triangular part of $H$ in either the sparse co-ordinate, or the sparse row-wise storage scheme. It need not be set when the dense, diagonal or (scaled) identity storage schemes are used, and in this case can be NULL.
H_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 $H$, 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.
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’, ‘dense’ or ‘absent’, the latter if access to the Jacobian is via matrix-vector products; lower or upper case variants are allowed.
A_ne	is a scalar variable of type ipc_, that holds the number of entries in $A$ in the sparse co-ordinate storage scheme. It need not be set for any of the other schemes.
A_row	is a one-dimensional array of size A_ne and type ipc_, that holds the row indices of $A$ in the sparse co-ordinate storage scheme. It need not be set for any of the other schemes, and in this case can be NULL.
A_col	is a one-dimensional array of size A_ne and type ipc_, that holds the column indices of $A$ in either the sparse co-ordinate, or the sparse row-wise storage scheme. It need not be set when the dense or diagonal storage schemes are used, and in this case can be NULL.
A_ptr	is a one-dimensional array of size n+1 and type ipc_, that holds the starting position of each row 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.
C_type	is a one-dimensional array of type char that specifies the symmetric storage scheme used for the matrix $C$. It should be one of ‘coordinate’, ‘sparse_by_rows’, ‘dense’, ‘diagonal’, ‘scaled_identity’, ‘identity’, ‘zero’ or ‘none’, the latter pair if $C=0$; lower or upper case variants are allowed.
C_ne	is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of $C$ in the sparse co-ordinate storage scheme. It need not be set for any of the other schemes.
C_row	is a one-dimensional array of size C_ne and type ipc_, that holds the row indices of the lower triangular part of $C$ 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.
C_col	is a one-dimensional array of size C_ne and type ipc_, that holds the column indices of the lower triangular part of $C$ in either the sparse co-ordinate, or the sparse row-wise storage scheme. It need not be set when the dense, diagonal or (scaled) identity storage schemes are used, and in this case can be NULL.
C_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 $C$, 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 sbls_reset_control(
    struct sbls_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 sbls_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:

0
The import was successful.

void sbls_factorize_matrix(
    void **data,
    ipc_ *status,
    ipc_ n,
    ipc_ h_ne,
    const rpc_ H_val[],
    ipc_ a_ne,
    const rpc_ A_val[],
    ipc_ c_ne,
    const rpc_ C_val[],
    const rpc_ D[]
)

Form and factorize the block matrix

\[\begin{split}K_{G} = \begin{pmatrix}G & A^T \\ A & - C\end{pmatrix}\end{split}\]

for some appropriate matrix $G$.

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: 0 The factors were generated successfully. -1 An allocation error occurred. A message indicating the offending array is written on unit control.error, and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -2 A deallocation error occurred. A message indicating the offending array is written on unit control.error and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -3 The restrictions n > 0 and m > 0 or requirement that a type contains its relevant string ‘dense’, ‘coordinate’, ‘sparse_by_rows’, ‘diagonal’, ‘scaled_identity’, ‘identity’, ‘zero’ or ‘none’ has been violated. -9 An error was reported by SLS analyse. The return status from SLS analyse is given in inform.sls_inform.status. See the documentation for the GALAHAD package SLS for further details. -10 An error was reported by SLS_factorize. The return status from SLS factorize is given in inform.sls_inform.status. See the documentation for the GALAHAD package SLS for further details. -13 An error was reported by ULS_factorize. The return status from ULS_factorize is given in inform.uls_factorize_status. See the documentation for the GALAHAD package ULS for further details. -15 The computed preconditioner $K_G$ is singular and is thus unsuitable. -20 The computed preconditioner $K_G$ has the wrong inertia and is thus unsuitable. -24 An error was reported by the GALAHAD package SORT_reorder_by_rows. The return status from SORT_reorder_by_rows is given in inform.sort_status. See the documentation for the GALAHAD package SORT for further details.
n	is a scalar variable of type ipc_, that holds the number of rows in the symmetric matrix $H$.
h_ne	is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of the symmetric matrix $H$.
H_val	is a one-dimensional array of size h_ne and type rpc_, that holds the values of the entries of the lower triangular part of the symmetric matrix $H$ in any of the available storage schemes
a_ne	is a scalar variable of type ipc_, that holds the number of entries in the unsymmetric matrix $A$.
A_val	is a one-dimensional array of size a_ne and type rpc_, that holds the values of the entries of the unsymmetric matrix $A$ in any of the available storage schemes.
c_ne	is a scalar variable of type ipc_, that holds the number of entries in the lower triangular part of the symmetric matrix $C$.
C_val	is a one-dimensional array of size c_ne and type rpc_, that holds the values of the entries of the lower triangular part of the symmetric matrix $C$ in any of the available storage schemes
D	is a one-dimensional array of size n and type rpc_, that holds the values of the entries of the diagonal matrix $D$ that is required if the user has specified control.preconditioner = 5. It need not be set otherwise.

void sbls_solve_system(void **data, ipc_ *status, ipc_ n, ipc_ m, rpc_ sol[])

Solve the block linear system

\[\begin{split}\begin{pmatrix}G & A^T \\ A & - C\end{pmatrix} \begin{pmatrix}x \\ y\end{pmatrix} = \begin{pmatrix}a \\ b\end{pmatrix}.\end{split}\]

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: 0 The required solution was obtained. -1 An allocation error occurred. A message indicating the offending array is written on unit control.error, and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -2 A deallocation error occurred. A message indicating the offending array is written on unit control.error and the returned allocation status and a string containing the name of the offending array are held in inform.alloc_status and inform.bad_alloc respectively. -11 An error was reported by SLS_solve. The return status from SLS solve is given in inform.sls_inform.status. See the documentation for the GALAHAD package SLS for further details. -14 An error was reported by ULS_solve. The return status from ULS_solve is given in inform.uls_solve_status. See the documentation for the GALAHAD package ULS for further details.
n	is a scalar variable of type ipc_, that holds the number of entries in the vector $a$.
m	is a scalar variable of type ipc_, that holds the number of entries in the vector $b$.
sol	is a one-dimensional array of size n + m and type double. on entry, its first n entries must hold the vector $a$, and the following entries must hold the vector $b$. On a successful exit, its first n entries contain the solution components $x$, and the following entries contain the components $y$.

void sbls_information(void **data, struct sbls_inform_type* inform, ipc_ *status)

Provides output information

Parameters:

data

holds private internal data

inform

is a struct containing output information (see sbls_inform_type)

status

is a scalar variable of type ipc_, that gives the exit status from the package. Possible values are (currently):

0
The values were recorded successfully

void sbls_terminate(
    void **data,
    struct sbls_control_type* control,
    struct sbls_inform_type* inform
)

Deallocate all internal private storage

Parameters:

data	holds private internal data
control	is a struct containing control information (see sbls_control_type)
inform	is a struct containing output information (see sbls_inform_type)