Environment

Routines for environmentally controlled parameters. More...

Data Structures
struct	starsh_params
	Structure for built-in STARS-H parameters. More...

Functions
int	starsh_init ()
	Initialize backend and low-rank engine to be used. More...
int	starsh_set_backend (const char *string)
	Set backend (MPI or OpenMP or other scheduler) for computations. More...
int	starsh_set_lrengine (const char *string)
	Set low-rank engine (SVD, Randomized SVD or Cross) for computations. More...
int	starsh_set_oversample (const char *string)
	Set oversampling size for randomized SVD and RRQR. More...

Variables
struct starsh_params	starsh_params
	Built-in parameters of STARS-H, accessible through environment.

Detailed Description

Routines for environmentally controlled parameters.

Function Documentation

starsh_init()

int starsh_init

(

)

Initialize backend and low-rank engine to be used.

Read environment variables and sets up backend (etc. MPI) and low-rank engine (etc. SVD).

Environment variables

STARSH_BACKEND: SEQUENTIAL, MPI (pure MPI), OPENMP (pure OpenMP) or MPI_OPENMP (hybrid MPI with OpenMP).

STARSH_LRENGINE: SVD (divide-and-conquer SVD), RRQR (LAPACK *geqp3) or RSVD (randomized SVD).

STARSH_OVERSAMPLE: Number of oversampling vectors for randomized SVD and RRQR.

Returns

Error code STARSH_ERRNO.

See also

starsh_set_backend(), starsh_set_lrengine().

starsh_set_backend()

int starsh_set_backend

(

const char *

string

)

Set backend (MPI or OpenMP or other scheduler) for computations.

Parameters

[in]

string

Environment variable and value, encoded in a string. Example: "STARSH_BACKEND=SEQUENTIAL".

Returns

Error code STARSH_ERRNO.

See also

starsh_init(), starsh_set_lrengine().

starsh_set_lrengine()

int starsh_set_lrengine

(

const char *

string

)

Set low-rank engine (SVD, Randomized SVD or Cross) for computations.

Parameters

[in]

string

Environment variable and value, encoded in a string. Example: "STARSH_LRENGINE=SVD".

Returns

Error code STARSH_ERRNO.

See also

starsh_init(), starsh_set_backends().

starsh_set_oversample()

int starsh_set_oversample

(

const char *

string

)

Set oversampling size for randomized SVD and RRQR.

Parameters

[in]

string

Environment variable and value, encoded in a string. Example: "STARSH_OVERSAMPLE=10".

Returns

Error code STARSH_ERRNO.

See also

starsh_init().