overview of functions provided#

// namespaces

namespace conf;

// typedefs

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

// structs

struct lhs_control_type;
struct lhs_inform_type;

// global functions

void lhs_initialize(
    void **data,
    struct lhs_control_type* control,
    struct lhs_inform_type* inform
);

void lhs_read_specfile(struct lhs_control_type* control, const char specfile[]);

void lhs_ihs(
    ipc_ n_dimen,
    ipc_ n_points,
    ipc_ *seed,
    int** X,
    const struct lhs_control_type* control,
    struct lhs_inform_type* inform,
    void **data
);

void lhs_get_seed(int *seed);
void lhs_information(void **data, struct lhs_inform_type* inform, ipc_ *status);

void lhs_terminate(
    void **data,
    struct lhs_control_type* control,
    struct lhs_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 lhs_initialize(
    void **data,
    struct lhs_control_type* control,
    struct lhs_inform_type* inform
)

Set default control values and initialize private data

Parameters:

data

holds private internal data

control

is a struct containing control information (see fit_control_type)

inform

is a struct containing output information (see fit_inform_type)

void lhs_read_specfile(struct lhs_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/lhs/LHS.template. See also Table 2.1 in the Fortran documentation provided in $GALAHAD/doc/lhs.pdf for a list of how these keywords relate to the components of the control structure.

Parameters:

control

a struct containing control information (see above)

specfile

a character string containing the name of the specfile

void lhs_ihs(
    ipc_ n_dimen,
    ipc_ n_points,
    ipc_ *seed,
    int** X,
    const struct lhs_control_type* control,
    struct lhs_inform_type* inform,
    void **data
)

The improved distributed hyper-cube sampling algorithm.

Discussion:

n_points points in an n_dimen dimensional Latin hyper-cube are to be selected. Each of the coordinate dimensions is discretized to the values 1 through n. The points are to be chosen in such a way that no two points have any coordinate value in common. This is a standard Latin hypercube requirement, and there are many solutions.

This algorithm differs in that it tries to pick a solution which has the property that the points are “spread out” as evenly as possible. It does this by determining an optimal even spacing, and using the DUPLICATION factor to allow it to choose the best of the various options available to it.

Reference:

Brian Beachkofski, Ramana Grandhi, Improved Distributed Hypercube Sampling, American Institute of Aeronautics and Astronautics Paper 2002-1274

Parameters:

n_dimen

is a scalar variable of type ipc_ that specifies the spatial dimension

n_points

is a scalar variable of type ipc_ that specifies the number of points to be generated

seed

is a scalar variable of type ipc_, that gives a seed for the random number generator used

X

is an array variable of type ipc_ with dimensions [n_dimen][n_points] that gives the hyper-cube points

control

inform

data

  • see lhs_initialize

void lhs_get_seed(int *seed)

Get a seed for the random number generator.

Parameters:

seed

is a scalar variable of type ipc_ that gives the pseudorandom seed value.

void lhs_information(void **data, struct lhs_inform_type* inform, ipc_ *status)

Provides output information

Parameters:

data

holds private internal data

inform

is a struct containing output information (see lhs_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 lhs_terminate(
    void **data,
    struct lhs_control_type* control,
    struct lhs_inform_type* inform
)

Deallocate all internal private storage

Parameters:

data

holds private internal data

control

is a struct containing control information (see lhs_control_type)

inform

is a struct containing output information (see lhs_inform_type)