callable functions#
function uls_initialize(T, solver, data, control, status)
Set default control values and initialize private data
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 ‘gls’, ‘ma28’, ‘ma48 or ‘getr’; lower or upper case variants are allowed. |
data |
holds private internal data |
control |
is a structure containing control information (see uls_control_type) |
status |
is a scalar variable of type Int32 that gives the exit status from the package. Possible values are:
|
function uls_read_specfile(T, 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/uls/ULS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/uls.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 uls_control_type) |
specfile |
is a one-dimensional array of type Vararg{Cchar} that must give the name of the specification file |
function uls_factorize_matrix(T, control, data, status, m, n, type, ne, val, row, col, ptr)
Import matrix data into internal storage prior to solution, analyse the sparsity patern, and subsequently factorize the matrix
Parameters:
control |
is a structure whose members provide control parameters for the remaining procedures (see uls_control_type) |
data |
holds private internal data |
status |
is a scalar variable of type Int32 that gives the exit status from the package. Possible values are:
|
m |
is a scalar variable of type Int32 that holds the number of rows in the unsymmetric matrix \(A\). |
n |
is a scalar variable of type Int32 that holds the number of columns in the unsymmetric matrix \(A\). |
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’ or ‘dense’; lower or upper case variants are allowed. |
ne |
is a scalar variable of type Int32 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. |
val |
is a one-dimensional array of size ne and type T, that holds the values of the entries of the matrix \(A\) in any of the supported storage schemes. |
row |
is a one-dimensional array of size ne and type Int32 that holds the row indices of the matrix \(A\) 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 Int32 that holds the column indices of the matrix \(A\) in either the sparse co-ordinate, or the sparse row-wise storage scheme. It need not be set when the dense storage schemes is used, and in this case can be C_NULL. |
ptr |
is a one-dimensional array of size m+1 and type Int32 that holds the starting position of each row of the matrix \(A\), 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 uls_reset_control(T, 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 uls_control_type) |
data |
holds private internal data |
status |
is a scalar variable of type Int32 that gives the exit status from the package. Possible values are:
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function uls_solve_system(T, data, status, m, n, sol, trans)
Solve the linear system \(Ax=b\) or \(A^Tx=b\).
Parameters:
data |
holds private internal data |
status |
is a scalar variable of type Int32 that gives the exit status from the package. Possible values are:
|
m |
is a scalar variable of type Int32 that holds the number of rows in the unsymmetric matrix \(A\). |
n |
is a scalar variable of type Int32 that holds the number of columns in the unsymmetric matrix \(A\). |
sol |
is a one-dimensional array of size n and type T. On entry, it must hold the vector \(b\). On a successful exit, its contains the solution \(x\). |
trans |
is a scalar variable of type Bool, that specifies whether to solve the equation \(A^Tx=b\) (trans=true) or \(Ax=b\) (trans=false). |
function uls_information(T, data, inform, status)
Provides output information
Parameters:
data |
holds private internal data |
inform |
is a structure containing output information (see uls_inform_type) |
status |
is a scalar variable of type Int32 that gives the exit status from the package. Possible values are (currently):
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function uls_terminate(T, data, control, inform)
Deallocate all internal private storage
Parameters:
data |
holds private internal data |
control |
is a structure containing control information (see uls_control_type) |
inform |
is a structure containing output information (see uls_inform_type) |