callable functions

    function sls_initialize(T, INT, solver, data, control, status)

Select solver, set default control values and initialize private data

Parameters:

solver	is a one-dimensional array of type Vararg{Cchar} 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.
data	holds private internal data
control	is a structure containing control information (see sls_control_type)
status	is a scalar variable of type INT that gives the exit status from the package. Possible values are: 0 The initialization was successful. -26 The requested solver is not available.

    function sls_read_specfile(T, INT, control, 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 structure containing control information (see sls_control_type)
specfile	is a one-dimensional array of type Vararg{Cchar} that must give the name of the specification file

    function sls_analyse_matrix(T, INT, control, data, status, n, type, ne, row, col, ptr)

Import structural matrix data into internal storage prior to solution

Parameters:

control	is a structure whose members provide control parameters for the remaining procedures (see sls_control_type)
data	holds private internal data
status	is a scalar variable of type INT 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 INT that holds the number of rows in the symmetric matrix $A$.
type	is a one-dimensional array of type Vararg{Cchar} 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 INT 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 INT 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 C_NULL.
col	is a one-dimensional array of size ne and type INT 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 C_NULL.
ptr	is a one-dimensional array of size n+1 and type INT 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 C_NULL.

    function sls_reset_control(T, INT, control, data, status)

Reset control parameters after import if required.

Parameters:

control	is a structure whose members provide control parameters for the remaining procedures (see sls_control_type)
data	holds private internal data
status	is a scalar variable of type INT that gives the exit status from the package. Possible values are: The import was successful.

    function sls_factorize_matrix(T, INT, data, status, ne, val)

Form and factorize the symmetric matrix $A$.

Parameters:

data	holds private internal data
status	is a scalar variable of type INT 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 INT 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 T that holds the values of the entries of the lower triangular part of the symmetric matrix $A$ in any of the supported storage schemes.

    function sls_solve_system(T, INT, data, status, n, sol)

Solve the linear system $Ax=b$.

Parameters:

data	holds private internal data
status	is a scalar variable of type INT 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 INT 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 $x$.

    function sls_partial_solve_system(T, INT, part, data, status, n, sol)

Given the factorization $A=LDU$ 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 Vararg{Cchar} 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 INT 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 INT 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 $x$.

    function sls_information(T, INT, data, inform, status)

Provide output information

Parameters:

data	holds private internal data
inform	is a structure containing output information (see sls_inform_type)
status	is a scalar variable of type INT that gives the exit status from the package. Possible values are (currently): 0 The values were recorded successfully

    function sls_terminate(T, INT, data, control, inform)

Deallocate all internal private storage

Parameters:

data	holds private internal data
control	is a structure containing control information (see sls_control_type)
inform	is a structure containing output information (see sls_inform_type)