callable functions#

    function eqp_initialize(T, 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 eqp_control_type)

status

is a scalar variable of type Int32 that gives the exit status from the package. Possible values are (currently):

  • 0

    The initialization was successful.

    function eqp_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/eqp/EQP.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/eqp.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 eqp_control_type)

specfile

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

    function eqp_import(T, 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)

Import problem data into internal storage prior to solution.

Parameters:

control

is a structure whose members provide control parameters for the remaining procedures (see eqp_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:

  • 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.

  • -23

    An entry from the strict upper triangle of \(H\) has been specified.

n

is a scalar variable of type Int32 that holds the number of variables.

m

is a scalar variable of type Int32 that holds the number of general linear constraints.

H_type

is a one-dimensional array of type Vararg{Cchar} that specifies the symmetric storage scheme used for the Hessian, \(H\). 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 Int32 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 Int32 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 Int32 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 Int32 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 constraint Jacobian, \(A\). It should be one of ‘coordinate’, ‘sparse_by_rows’ or ‘dense; lower or upper case variants are allowed.

A_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.

A_row

is a one-dimensional array of size A_ne and type Int32 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 Int32 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 Int32 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.

    function eqp_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 eqp_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:

  • 0

    The import was successful.

    function eqp_solve_qp(T, data, status, n, m, h_ne, H_val, g, f,
                          a_ne, A_val, c, x, y)

Solve the quadratic program when the Hessian \(H\) is available.

Parameters:

data

holds private internal data

status

is a scalar variable of type Int32 that gives the entry and exit status from the package.

Possible exit values are:

  • 0

    The run 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 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.

  • -7

    The constraints appear to have no feasible point.

  • -9

    The analysis phase of the factorization failed; the return status from the factorization package is given in the component inform.factor_status

  • -10

    The factorization failed; the return status from the factorization package is given in the component inform.factor_status.

  • -11

    The solution of a set of linear equations using factors from the factorization package failed; the return status from the factorization package is given in the component inform.factor_status.

  • -16

    The problem is so ill-conditioned that further progress is impossible.

  • -17

    The step is too small to make further impact.

  • -18

    Too many iterations have been performed. This may happen if control.maxit is too small, but may also be symptomatic of a badly scaled problem.

  • -19

    The CPU time limit has been reached. This may happen if control.cpu_time_limit is too small, but may also be symptomatic of a badly scaled problem.

  • -23

    An entry from the strict upper triangle of \(H\) has been specified.

n

is a scalar variable of type Int32 that holds the number of variables

m

is a scalar variable of type Int32 that holds the number of general linear constraints.

h_ne

is a scalar variable of type Int32 that holds the number of entries in the lower triangular part of the Hessian 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 Hessian matrix \(H\) in any of the available storage schemes.

g

is a one-dimensional array of size n and type T that holds the linear term \(g\) of the objective function. The j-th component of g, j = 1, … , n, contains \(g_j\).

f

is a scalar of type T that holds the constant term \(f\) of the objective function.

a_ne

is a scalar variable of type Int32 that holds the number of entries in the constraint Jacobian 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 constraint Jacobian matrix \(A\) in any of the available storage schemes.

c

is a one-dimensional array of size m and type T that holds the linear term \(c\) in the constraints. The i-th component of c, i = 1, … , m, contains \(c_i\).

x

is a one-dimensional array of size n and type T that holds the values \(x\) of the optimization variables. The j-th component of x, j = 1, … , n, contains \(x_j\).

y

is a one-dimensional array of size n and type T that holds the values \(y\) of the Lagrange multipliers for the linear constraints. The j-th component of y, i = 1, … , m, contains \(y_i\).

    function eqp_solve_sldqp(T, data, status, n, m, w, x0, g, f,
                             a_ne, A_val, c, x, y)

Solve the shifted least-distance quadratic program

Parameters:

data

holds private internal data

status

is a scalar variable of type Int32 that gives the entry and exit status from the package.

Possible exit values are:

  • 0

    The run 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 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.

  • -7

    The constraints appear to have no feasible point.

  • -9

    The analysis phase of the factorization failed; the return status from the factorization package is given in the component inform.factor_status

  • -10

    The factorization failed; the return status from the factorization package is given in the component inform.factor_status.

  • -11

    The solution of a set of linear equations using factors from the factorization package failed; the return status from the factorization package is given in the component inform.factor_status.

  • -16

    The problem is so ill-conditioned that further progress is impossible.

  • -17

    The step is too small to make further impact.

  • -18

    Too many iterations have been performed. This may happen if control.maxit is too small, but may also be symptomatic of a badly scaled problem.

  • -19

    The CPU time limit has been reached. This may happen if control.cpu_time_limit is too small, but may also be symptomatic of a badly scaled problem.

  • -23

    An entry from the strict upper triangle of \(H\) has been specified.

n

is a scalar variable of type Int32 that holds the number of variables

m

is a scalar variable of type Int32 that holds the number of general linear constraints.

w

is a one-dimensional array of size n and type T that holds the values of the weights \(w\).

x0

is a one-dimensional array of size n and type T that holds the values of the shifts \(x^0\).

g

is a one-dimensional array of size n and type T that holds the linear term \(g\) of the objective function. The j-th component of g, j = 1, … , n, contains \(g_j\).

f

is a scalar of type T that holds the constant term \(f\) of the objective function.

a_ne

is a scalar variable of type Int32 that holds the number of entries in the constraint Jacobian 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 constraint Jacobian matrix \(A\) in any of the available storage schemes.

c

is a one-dimensional array of size m and type T that holds the linear term \(c\) in the constraints. The i-th component of c, i = 1, … , m, contains \(c_i\).

x

is a one-dimensional array of size n and type T that holds the values \(x\) of the optimization variables. The j-th component of x, j = 1, … , n, contains \(x_j\).

y

is a one-dimensional array of size n and type T that holds the values \(y\) of the Lagrange multipliers for the linear constraints. The j-th component of y, i = 1, … , m, contains \(y_i\).

    function eqp_resolve_qp(T, data, status, n, m, g, f, c, x, y)

Resolve the quadratic program or shifted least-distance quadratic program when some or all of the data \(g\), \(f\) and \(c\) has changed

Parameters:

data

holds private internal data

status

is a scalar variable of type Int32 that gives the entry and exit status from the package.

Possible exit values are:

  • 0

    The run 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 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.

  • -7

    The constraints appear to have no feasible point.

  • -11

    The solution of a set of linear equations using factors from the factorization package failed; the return status from the factorization package is given in the component inform.factor_status.

  • -16

    The problem is so ill-conditioned that further progress is impossible.

  • -17

    The step is too small to make further impact.

  • -18

    Too many iterations have been performed. This may happen if control.maxit is too small, but may also be symptomatic of a badly scaled problem.

  • -19

    The CPU time limit has been reached. This may happen if control.cpu_time_limit is too small, but may also be symptomatic of a badly scaled problem.

  • -23

    An entry from the strict upper triangle of \(H\) has been specified.

n

is a scalar variable of type Int32 that holds the number of variables

m

is a scalar variable of type Int32 that holds the number of general linear constraints.

g

is a one-dimensional array of size n and type T that holds the linear term \(g\) of the objective function. The j-th component of g, j = 1, … , n, contains \(g_j\).

f

is a scalar of type T that holds the constant term \(f\) of the objective function.

c

is a one-dimensional array of size m and type T that holds the linear term \(c\) in the constraints. The i-th component of c, i = 1, … , m, contains \(c_i\).

x

is a one-dimensional array of size n and type T that holds the values \(x\) of the optimization variables. The j-th component of x, j = 1, … , n, contains \(x_j\).

y

is a one-dimensional array of size n and type T that holds the values \(y\) of the Lagrange multipliers for the linear constraints. The j-th component of y, i = 1, … , m, contains \(y_i\).

    function eqp_information(T, data, inform, status)

Provides output information

Parameters:

data

holds private internal data

inform

is a structure containing output information (see eqp_inform_type)

status

is a scalar variable of type Int32 that gives the exit status from the package. Possible values are (currently):

  • 0

    The values were recorded successfully

    function eqp_terminate(T, data, control, inform)

Deallocate all internal private storage

Parameters:

data

holds private internal data

control

is a structure containing control information (see eqp_control_type)

inform

is a structure containing output information (see eqp_inform_type)