overview of functions provided#

// typedefs

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

// structs

struct sls_control_type;
struct sls_inform_type;
struct sls_time_type;

// global functions

void sls_initialize(
    const char solver[],
    void **data,
    struct sls_control_type* control,
    ipc_ *status
);

void sls_read_specfile(struct sls_control_type* control, const char specfile[]);

void sls_analyse_matrix(
    struct sls_control_type* control,
    void **data,
    ipc_ *status,
    ipc_ n,
    const char type[],
    ipc_ ne,
    const ipc_ row[],
    const ipc_ col[],
    const ipc_ ptr[]
);

void sls_reset_control(
    struct sls_control_type* control,
    void **data,
    ipc_ *status
);

void sls_factorize_matrix(
    void **data,
    ipc_ *status,
    ipc_ ne,
    const rpc_ val[]
);

void sls_solve_system(void **data, ipc_ *status, ipc_ n, rpc_ sol[]);

void sls_partial_solve_system(
    const char part[],
    void **data,
    ipc_ *status,
    ipc_ n,
    rpc_ sol[]
);

void sls_information(void **data, struct sls_inform_type* inform, ipc_ *status);

void sls_terminate(
    void **data,
    struct sls_control_type* control,
    struct sls_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 SINGLE.

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 calls#

void sls_initialize(
    const char solver[],
    void **data,
    struct sls_control_type* control,
    ipc_ *status
)

Select solver, set default control values and initialize private data

Parameters:

solver

is a one-dimensional array of type char that specifies the solver package that should be used to factorize the matrix \(A\). It should be one of ‘sils’, ‘ma27’, ‘ma57’, ‘ma77’, ‘ma86’, ‘ma87’, ‘ma97’, ‘ssids’, ‘mumps’, ‘pardiso’, ‘mkl pardiso’, ‘pastix’, ‘wsmp’, ‘potr’, ‘sytr’ or ‘pbtr’; lower or upper case variants are allowed. Only ‘potr’, ‘sytr’, ‘pbtr’ and, for OMP 4.0-compliant compilers, ‘ssids’ are installed by default, but others are easily installed (see README.external).

data

holds private internal data

control

is a struct containing control information (see sls_control_type)

status

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

  • 0

    The initialization was successful.

  • -26

    The requested solver is not available.

void sls_read_specfile(struct sls_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/sls/SLS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/sls.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 sls_control_type)

specfile

is a character string containing the name of the specification file

void sls_analyse_matrix(
    struct sls_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 sls_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 and analysis were conducted 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 or requirement that the matrix type must contain the relevant string ‘dense’, ‘coordinate’ or ‘sparse_by_rows has been violated.

  • -20

    The matrix is not positive definite while the solver used expected it to be.

  • -26

    The requested solver is not available.

  • -29

    This option is not available with this solver.

  • -32

    More than control.max integer factor size words of internal integer storage are required for in-core factorization.

  • -34

    The package PARDISO failed; check the solver-specific information components inform.pardiso iparm and inform.pardiso_dparm along with PARDISO’s documentation for more details.

  • -35

    The package WSMP failed; check the solver-specific information components inform.wsmp_iparm and inform.wsmp dparm along with WSMP’s documentation for more details.

  • -36

    The scaling package HSL MC64 failed; check the solver-specific information component inform.mc64_info along with HSL MC64’s documentation for more details.

  • -37

    The scaling package MC77 failed; check the solver-specific information components inform.mc77 info and inform.mc77_rinfo along with MC77’s documentation for more details.

  • -43

    A direct-access file error occurred. See the value of inform.ma77_info.flag for more details.

  • -50

    A solver-specific error occurred; check the solver-specific information component of inform along with the solver’s documentation for more details.

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 sls_reset_control(
    struct sls_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 sls_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:

    1. The import was successful.

void sls_factorize_matrix(
    void **data,
    ipc_ *status,
    ipc_ ne,
    const rpc_ val[]
)

Form and factorize the symmetric 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:

  • 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 or requirement that the matrix type must contain the relevant string ‘dense’, ‘coordinate’ or ‘sparse_by_rows has been violated.

  • -20

    The matrix is not positive definite while the solver used expected it to be.

  • -26

    The requested solver is not available.

  • -29

    This option is not available with this solver.

  • -32

    More than control.max integer factor size words of internal integer storage are required for in-core factorization.

  • -34

    The package PARDISO failed; check the solver-specific information components inform.pardiso iparm and inform.pardiso_dparm along with PARDISO’s documentation for more details.

  • -35

    The package WSMP failed; check the solver-specific information components inform.wsmp_iparm and inform.wsmp dparm along with WSMP’s documentation for more details.

  • -36

    The scaling package HSL MC64 failed; check the solver-specific information component inform.mc64_info along with HSL MC64’s documentation for more details.

  • -37

    The scaling package MC77 failed; check the solver-specific information components inform.mc77 info and inform.mc77_rinfo along with MC77’s documentation for more details.

  • -43

    A direct-access file error occurred. See the value of inform.ma77_info.flag for more details.

  • -50

    A solver-specific error occurred; check the solver-specific information component of inform along with the solver’s documentation for more details.

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

Solve the linear system \(Ax=b\).

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:

  • 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.

  • -34

    The package PARDISO failed; check the solver-specific information components inform.pardiso iparm and inform.pardiso_dparm along with PARDISO’s documentation for more details.

  • -35

    The package WSMP failed; check the solver-specific information components inform.wsmp_iparm and inform.wsmp dparm along with WSMP’s documentation for more details.

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 \(x\).

void sls_partial_solve_system(
    const char part[],
    void **data,
    ipc_ *status,
    ipc_ n,
    rpc_ sol[]
)

Given the factorization \(A = L D U\) with \(U = L^T\), solve the linear system \(Mx=b\), where \(M\) is one of \(L\), \(D\), \(U\) or \(S = L \sqrt{D}\).

Parameters:

part

is a one-dimensional array of type char that specifies the component \(M\) of the factorization that is to be used. It should be one of “L”, “D”, “U” or “S”, and these correspond to the parts \(L\), \(D\), \(U\) and \(S\); lower or upper case variants are allowed.

data

holds private internal data

status

is a scalar variable of type ipc_, that gives the entry and exit status from the package.

On initial entry, status must be set to 1.

Possible exit 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.

  • -34

    The package PARDISO failed; check the solver-specific information components inform.pardiso iparm and inform.pardiso_dparm along with PARDISO’s documentation for more details.

  • -35

    The package WSMP failed; check the solver-specific information components inform.wsmp_iparm and inform.wsmp dparm along with WSMP’s documentation for more details.

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 \(x\).

void sls_information(void **data, struct sls_inform_type* inform, ipc_ *status)

Provide output information

Parameters:

data

holds private internal data

inform

is a struct containing output information (see sls_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 sls_terminate(
    void **data,
    struct sls_control_type* control,
    struct sls_inform_type* inform
)

Deallocate all internal private storage

Parameters:

data

holds private internal data

control

is a struct containing control information (see sls_control_type)

inform

is a struct containing output information (see sls_inform_type)