callable functions#

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

Set default control values and initialize private data

Parameters:

data

holds private internal data

control

is a structure containing control information (see ssls_control_type)

status

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

  • 0

    The initialization was successful.

    function ssls_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/ssls/SSLS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/ssls.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 ssls_control_type)

specfile

is a one-dimensional array of type Vararg{Cchar} that must give the name of the specification file

    function ssls_import(T, INT, control, data, status, n, m,
                         H_type, H_ne, H_row, H_col, H_ptr,
                         A_type, A_ne, A_row, A_col, A_ptr,
                         C_type, C_ne, C_row, C_col, C_ptr)

Import structural matrix data into internal storage prior to solution and analyse the resuting structure.

Parameters:

control

is a structure whose members provide control parameters for the remaining procedures (see ssls_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 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.

  • -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.

n

is a scalar variable of type INT that holds the number of rows in the symmetric matrix \(H\).

m

is a scalar variable of type INT that holds the number of rows in the symmetric matrix \(C\).

H_type

is a one-dimensional array of type Vararg{Cchar} 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 INT 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 INT 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 C_NULL.

H_col

is a one-dimensional array of size H_ne and type INT 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 C_NULL.

H_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 \(H\), 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 C_NULL.

A_type

is a one-dimensional array of type Vararg{Cchar} that specifies the unsymmetric 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 INT 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 INT 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 C_NULL.

A_col

is a one-dimensional array of size A_ne and type INT 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 C_NULL.

A_ptr

is a one-dimensional array of size n+1 and type INT 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 C_NULL.

C_type

is a one-dimensional array of type Vararg{Cchar} 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 INT 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 INT 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 C_NULL.

C_col

is a one-dimensional array of size C_ne and type INT 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 C_NULL.

C_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 \(C\), 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 C_NULL.

    function ssls_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 ssls_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 was successful.

    function ssls_factorize_matrix(T, INT, data, status, n, h_ne, H_val,
                                   a_ne, A_val, c_ne, C_val)

Form and factorize the block matrix

\[\begin{split}K = \begin{pmatrix}H & A^T \\ A & - C\end{pmatrix}.\end{split}\]

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 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.

  • -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.

n

is a scalar variable of type INT that holds the number of rows in the symmetric matrix \(H\).

h_ne

is a scalar variable of type INT 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 T 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 INT that holds the number of entries in the unsymmetric matrix \(A\).

A_val

is a one-dimensional array of size a_ne and type T 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 INT 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 T that holds the values of the entries of the lower triangular part of the symmetric matrix \(C\) in any of the available storage schemes

    function ssls_solve_system(T, INT, data, status, n, m, 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 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.

  • -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.

n

is a scalar variable of type INT that holds the number of entries in the vector \(a\).

m

is a scalar variable of type INT that holds the number of entries in the vector \(b\).

sol

is a one-dimensional array of size n + m and type T. 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 \(y\).

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

Provides output information

Parameters:

data

holds private internal data

inform

is a structure containing output information (see ssls_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 ssls_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 ssls_control_type)

inform

is a structure containing output information (see ssls_inform_type)