transi.h File Reference

C-interface to the IFS trans-library. More...

#include <stddef.h>
#include "ectrans/version.h"

Go to the source code of this file.

Classes
struct	Trans_t
	Struct that holds information to do transforms for one particular grid resolution. More...
struct	DirTrans_t
	Arguments structure for trans_dirtrans() More...
struct	DirTransAdj_t
	Arguments structure for trans_dirtrans_adj() More...
struct	InvTrans_t
	Arguments structure for trans_invtrans() More...
struct	InvTransAdj_t
	Adjoint of spectral inverse. More...
struct	DistGrid_t
	Arguments structure for trans_distgrid() More...
struct	GathGrid_t
	Arguments structure for trans_gathgrid() More...
struct	DistSpec_t
	Arguments structure for trans_distspec() More...
struct	GathSpec_t
	Arguments structure for trans_gathspec() More...
struct	VorDivToUV_t
	Arguments structure for trans_vordiv_to_UV() More...
struct	SpecNorm_t

Macros
#define	TRANS_FFT992   1
#define	TRANS_FFTW   2
#define	TRANS_SUCCESS   0

Typedefs
typedef int	_bool

Functions
const char *	trans_error_msg (int errcode)
	Get error message relating to error code.
int	trans_set_handles_limit (int limit)
	Set limit on maximum simultaneously allocated transforms.
int	trans_set_radius (double radius)
	Set radius of planet used in trans.
int	trans_set_nprtrv (int nprtrv)
	Set nprtrv for parallel distribution of fields in spectral space.
int	trans_use_mpi (_bool)
	Use MPI in trans library.
int	trans_init (void)
	Initialize trans library.
int	trans_set_read (struct Trans_t *, const char *filepath)
int	trans_set_write (struct Trans_t *, const char *filepath)
int	trans_set_cache (struct Trans_t *, const void *, size_t)
int	trans_setup (struct Trans_t *trans)
	Setup a new resolution to be used in the trans library.
int	trans_inquire (struct Trans_t *trans, const char *varlist)
	Inquire the trans library for array values.
int	trans_dirtrans (struct DirTrans_t *dirtrans)
	Direct spectral transform (from grid-point to spectral)
int	trans_dirtrans_adj (struct DirTransAdj_t *dirtransadj)
	Adjoint of the Direct spectral transform (from spectral to grid-point)
int	trans_invtrans (struct InvTrans_t *invtrans)
	Inverse spectral transform (from spectral grid-point)
int	trans_invtrans_adj (struct InvTransAdj_t *invtrans_adj)
	Adjoint of the Inverse spectral transform (from grid-point spectral)
int	trans_distgrid (struct DistGrid_t *distgrid)
	Distribute global gridpoint array among processors.
int	trans_gathgrid (struct GathGrid_t *gathgrid)
	Gather global gridpoint array from processors.
int	trans_distspec (struct DistSpec_t *distspec)
	Distribute global spectral array among processors.
int	trans_gathspec (struct GathSpec_t *gathspec)
	Gather global spectral array from processors.
int	trans_vordiv_to_UV (struct VorDivToUV_t *vordiv_to_UV)
	Convert Spectral vorticity & divergence to Spectral u*cos(theta) & v*cos(theta)
int	trans_specnorm (struct SpecNorm_t *specnorm)
	Compute global spectral norms.
int	trans_delete (struct Trans_t *trans)
	Remove footprint of specific resolution.
int	trans_finalize (void)
	Finalize trans library.
int	trans_new (struct Trans_t *)
	Constructor for Trans_t, setting default values.
int	trans_set_resol (struct Trans_t *trans, int ndgl, const int *nloen)
	Set gridpoint resolution for trans.
int	trans_set_resol_lonlat (struct Trans_t *trans, int nlon, int nlat)
	Set gridpoint resolution for trans for longitude-latitude grids.
int	trans_set_trunc (struct Trans_t *trans, int nsmax)
	Set spectral truncation wave number for trans.
struct DirTrans_t	new_dirtrans (struct Trans_t *trans)
	Constructor for DirTrans_t, resetting default values.
struct DirTransAdj_t	new_dirtrans_adj (struct Trans_t *trans)
	Constructor for DirTransAdj_t, resetting default values.
struct InvTrans_t	new_invtrans (struct Trans_t *trans)
	Constructor for InvTrans_t, resetting default values.
struct InvTransAdj_t	new_invtrans_adj (struct Trans_t *trans)
	Constructor for InvTransAdj_t, resetting default values.
struct DistGrid_t	new_distgrid (struct Trans_t *trans)
	Constructor for DistGrid_t, resetting default values.
struct GathGrid_t	new_gathgrid (struct Trans_t *trans)
	Constructor for GathGrid_t, resetting default values.
struct DistSpec_t	new_distspec (struct Trans_t *trans)
	Constructor for DistSpec_t, resetting default values.
struct GathSpec_t	new_gathspec (struct Trans_t *trans)
	Constructor for GathSpec_t, resetting default values.
struct VorDivToUV_t	new_vordiv_to_UV (void)
	Constructor for VorDivToUV_t, resetting default values.
struct SpecNorm_t	new_specnorm (struct Trans_t *trans)
	Constructor for SpecNorm_t, resetting default values.

Detailed Description

C-interface to the IFS trans-library.

This file declares the C-API to the IFS trans-library Definitions of routines are implemented in trans_module.F90, which redirects function calls to the IFS TRANS library

Author

Willem Deconinck (nawd)

Date

Jul 2014

Function Documentation

new_dirtrans()

struct DirTrans_t new_dirtrans

(

struct Trans_t *

trans

)

Constructor for DirTrans_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

DirTrans_t struct to be used as argument for trans_dirtrans()

new_dirtrans_adj()

struct DirTransAdj_t new_dirtrans_adj

(

struct Trans_t *

trans

)

Constructor for DirTransAdj_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

DirTransAdj_t struct to be used as argument for trans_dirtrans_adj()

new_distgrid()

struct DistGrid_t new_distgrid

(

struct Trans_t *

trans

)

Constructor for DistGrid_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

DistGrid_t struct to be used as argument for trans_distgrid()

new_distspec()

struct DistSpec_t new_distspec

(

struct Trans_t *

trans

)

Constructor for DistSpec_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

DistSpec_t struct to be used as argument for trans_distspec()

new_gathgrid()

struct GathGrid_t new_gathgrid

(

struct Trans_t *

trans

)

Constructor for GathGrid_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

GathGrid_t struct to be used as argument for trans_gathgrid()

new_gathspec()

struct GathSpec_t new_gathspec

(

struct Trans_t *

trans

)

Constructor for GathSpec_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

GathSpec_t struct to be used as argument for trans_gathspec()

new_invtrans()

struct InvTrans_t new_invtrans

(

struct Trans_t *

trans

)

Constructor for InvTrans_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

InvTrans_t struct to be used as argument for trans_invtrans()

new_invtrans_adj()

struct InvTransAdj_t new_invtrans_adj

(

struct Trans_t *

trans

)

Constructor for InvTransAdj_t, resetting default values.

Parameters

trans

[in] Trans_t used to set defaults

Returns

InvTransAdj_t struct to be used as argument for trans_invtrans_adj()

new_specnorm()

struct SpecNorm_t new_specnorm

(

struct Trans_t *

trans

)

Constructor for SpecNorm_t, resetting default values.

Returns

SpecNorm_t struct to be used as argument for trans_specnorm()

new_vordiv_to_UV()

struct VorDivToUV_t new_vordiv_to_UV

(

void

)

Constructor for VorDivToUV_t, resetting default values.

Returns

VorDivToUV_t struct to be used as argument for trans_gathspec()

trans_delete()

int trans_delete

(

struct Trans_t *

trans

)

Remove footprint of specific resolution.

Parameters

trans

Trans_t struct describing specific resolution

All arrays will be deallocated.

trans_dirtrans()

int trans_dirtrans

(

struct DirTrans_t *

dirtrans

)

Direct spectral transform (from grid-point to spectral)

A DirTrans_t struct, initialised with new_dirtrans(), groups all arguments

Parameters

dirtrans

DirTrans_t struct, containing all arguments.

Usage:

• Transform of scalar fields

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp       = malloc( sizeof(double) * nscalar*trans.ngptot );
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  struct DirTrans_t dirtrans = new_dirtrans(&trans);
    dirtrans.nscalar   = nscalar;   // input
    dirtrans.rgp       = rgp;       // input
    dirtrans.rspscalar = rspscalar; // output
  trans_dirtrans(&dirtrans);

• Transform of U and V fields to vorticity and divergence

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp    = malloc( sizeof(double) * 2*nvordiv*trans.ngptot );
  double* rspvor = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  struct DirTrans_t dirtrans = new_dirtrans(&trans);
    dirtrans.nvordiv   = nvordiv;  // input
    dirtrans.rgp       = rgp;      // input    --    order: U, V
    dirtrans.rspvor    = rspvor;   // output
    dirtrans.rspdiv    = rspdiv;   // output
  trans_dirtrans(&dirtrans);

• Transform of U and V fields to vorticity and divergence, as well as scalar fields

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp       = malloc( sizeof(double) * (2*nvordiv+nscalar)*trans.ngptot );
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  struct DirTrans_t dirtrans = new_dirtrans(&trans);
    dirtrans.nvordiv   = nvordiv;   // input
    dirtrans.nscalar   = nscalar;   // input
    dirtrans.rgp       = rgp;       // input   --   order: U, V, scalars
    dirtrans.rspscalar = rspscalar; // output
    dirtrans.rspvor    = rspvor;    // output
    dirtrans.rspdiv    = rspdiv;    // output
  trans_dirtrans(&dirtrans);

Note

trans_dirtrans works on distributed arrays

trans_dirtrans_adj()

int trans_dirtrans_adj

(

struct DirTransAdj_t *

dirtransadj

)

Adjoint of the Direct spectral transform (from spectral to grid-point)

A DirTransAdj_t struct, initialised with new_dirtrans_adj(), groups all arguments

Parameters

dirtrans_adj

DirTransAdj_t struct, containing all arguments.

Usage:

• Adjoint of Transform of scalar fields

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp       = malloc( sizeof(double) * nscalar*trans.ngptot );
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  struct DirTransAdj_t dirtrans_adj = new_dirtrans_adj(&trans);
    dirtrans_adj.nscalar   = nscalar;   // input
    dirtrans_adj.rgp       = rgp;       // input
    dirtrans_adj.rspscalar = rspscalar; // output
  trans_dirtrans_adj(&dirtrans_adj);

• Adjoint of Transform of U and V fields to vorticity and divergence

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp    = malloc( sizeof(double) * 2*nvordiv*trans.ngptot );
  double* rspvor = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  struct DirTransAdj_t dirtrans_adj = new_dirtrans_adj(&trans);
    dirtrans_adj.nvordiv   = nvordiv;  // input
    dirtrans_adj.rgp       = rgp;      // input    --    order: U, V
    dirtrans_adj.rspvor    = rspvor;   // output
    dirtrans_adj.rspdiv    = rspdiv;   // output
  trans_dirtrans_adj(&dirtrans_adj);

• Adjoint of Transform of U and V fields to vorticity and divergence, as well as scalar fields

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rgp       = malloc( sizeof(double) * (2*nvordiv+nscalar)*trans.ngptot );
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  struct DirTransAdj_t dirtrans_adj = new_dirtrans_adj(&trans);
    dirtrans_adj.nvordiv   = nvordiv;   // input
    dirtrans_adj.nscalar   = nscalar;   // input
    dirtrans_adj.rgp       = rgp;       // input   --   order: U, V, scalars
    dirtrans_adj.rspscalar = rspscalar; // output
    dirtrans_adj.rspvor    = rspvor;    // output
    dirtrans_adj.rspdiv    = rspdiv;    // output
  trans_dirtrans_adj(&dirtrans_adj);

Note

trans_dirtrans_adj works on distributed arrays

trans_distgrid()

int trans_distgrid

(

struct DistGrid_t *

distgrid

)

Distribute global gridpoint array among processors.

Usage:

struct Trans_t trans;
trans_new(&trans);
... // missing setup
int nfld = 1;
double* rgpg = NULL;
if( trans.myproc == 1 ) // Load global field in proc 1
{
  rgpg = malloc( sizeof(double) * trans.ngptotg*nfld );
  ... // load data in rgpg[nfld][ngptotg]
}
int* nfrom = malloc( sizeof(int) * nfld );
nfrom[0] = 1; // Global field 0 sits in proc 1
 
double* rgp  = malloc( sizeof(double) * nfld*trans.ngptot  );
struct DistGrid_t distgrid = new_distgrid(&trans);
  distgrid.nfrom = nfrom;
  distgrid.rgpg  = rgpg;
  distgrid.rgp   = rgp;
  distgrid.nfld  = nfld;
trans_distgrid(&distgrid);

trans_distspec()

int trans_distspec

(

struct DistSpec_t *

distspec

)

Distribute global spectral array among processors.

Usage:

struct Trans_t trans;
trans_new(&trans);
... // missing setup
 
// Global fields to be distributed
int nscalar = 1;
double* rspscalarg = NULL;
if( trans.myproc == 1 )
{
  rspscalarg = malloc( sizeof(double) * nscalar*trans.nspec2g );
  ... // load data in rspscalarg[nspec2g][nscalar]
}
int* nfrom = malloc( sizeof(int) * nscalar );
nfrom[0] = 1;
 
// Distribute to local fields
double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
struct DistSpec_t distspec = new_distspec(&trans);
  distspec.rspec  = rspscalar;
  distspec.rspecg = rspscalarg;
  distspec.nfld   = nscalar;
  distspec.nfrom  = nto;
trans_distspec(&distspec);

trans_finalize()

int trans_finalize

(

void

)

Finalize trans library.

This finalizes MPI communication, and deallocates resolution-independent storage. After this, no more calls to trans should be made

trans_gathgrid()

int trans_gathgrid

(

struct GathGrid_t *

gathgrid

)

Gather global gridpoint array from processors.

Usage:

struct Trans_t trans;
trans_new(&trans);
... // missing setup
 
// Distributed field
int nfld = 1;
double* rgp  = malloc( sizeof(double) * nfld*trans.ngptot  );
... // load data in rgp[nfld][ngptot]
 
// Global field
double* rgpg = NULL;
if( trans.myproc == 1 ) // We will gather to proc 1
{
  rgpg = malloc( sizeof(double) * nfld*trans.ngptotg );
}
int* nto = malloc( sizeof(int) * nfld );
nto[0] = 1;
 
// Gather global fields
struct GathGrid_t gathgrid = new_gathgrid(&trans);
  gathgrid.rgp  = rgp;
  gathgrid.rgpg = rgpg;
  gathgrid.nto  = nto;
  gathgrid.nfld = nfld;
trans_gathgrid(&gathgrid);

trans_gathspec()

int trans_gathspec

(

struct GathSpec_t *

gathspec

)

Gather global spectral array from processors.

Usage:

struct Trans_t trans;
trans_new(&trans);
... // missing setup
 
// We have some distributed spectral fields "rspscalar"
int nscalar = 1;
double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
... // load data in rspscalar[nspec2][nscalar]
 
// We want to gather to proc 1
double* rspscalarg = NULL;
if( trans.myproc == 1 )
  rspscalarg = malloc( sizeof(double) * nscalar*trans.nspec2g );
int* nto = malloc( sizeof(int) * nscalar );
nto[0] = 1;
struct GathSpec_t gathspec = new_gathspec(&trans);
  gathspec.rspec  = rspscalar;
  gathspec.rspecg = rspscalarg;
  gathspec.nfld   = nscalar;
  gathspec.nto    = nto;
trans_gathspec(&gathspec);

trans_init()

int trans_init

(

void

)

Initialize trans library.

This initializes MPI communication, and allocates resolution-independent storage.
If this routine is not called, then it will be called internally upon the first call to trans_setup()

Precondition

call trans_set_radius() and/or trans_set_nprtrv() if radius or nprtrv need to be different from default values

trans_inquire()

int trans_inquire	(	struct Trans_t *	trans,
		const char *	varlist )

Inquire the trans library for array values.

Parameters

trans	Trans_t struct which needs to have been setup using trans_setup()
varlist	comma-separated string of values to inquire

The inquired values will be allocated if needed, and filled in in the Trans_t struct

trans_invtrans()

int trans_invtrans

(

struct InvTrans_t *

invtrans

)

Inverse spectral transform (from spectral grid-point)

A InvTrans_t struct, initialised with new_invtrans(), groups all arguments

Parameters

invtrans

InvTrans_t struct, containing all arguments.

Usage:

• Transform of scalars

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * nscalar*trans.ngptot );
   
  // Inverse Transform
  struct InvTrans_t invtrans = new_invtrans(&trans);
    invtrans.nscalar   = nscalar;    // input
    invtrans.rspscalar = rspscalar;  // input
    invtrans.rgp       = rgp;        // output
  trans_invtrans(&invtrans);

• Transform vorticity and divergence to U and V

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * 2*nvordiv*trans.ngptot );
   
  // Inverse Transform
  struct InvTrans_t invtrans = new_invtrans(&trans);
    invtrans.nvordiv   = nvordiv;    // input
    invtrans.rspvor    = rspvor;     // input
    invtrans.rspdiv    = rspdiv;     // input
    invtrans.rgp       = rgp;        // output  --  order: u, v
  trans_invtrans(&invtrans);

• Transform of vorticity, divergence and scalars to U, V, scalars

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * (2*nvordiv+nscalar)*trans.ngptot );
   
  // Inverse Transform
  struct InvTrans_t invtrans = new_invtrans(&trans);
    invtrans.nscalar   = nscalar;    // input
    invtrans.nvordiv   = nvordiv;    // input
    invtrans.rspscalar = rspscalar;  // input
    invtrans.rspvor    = rspvor;     // input
    invtrans.rspdiv    = rspdiv;     // input
    invtrans.rgp       = rgp;        // output  --  order: u, v, scalars
  trans_invtrans(&invtrans);

Note

trans_invtrans works on distributed arrays

trans_invtrans_adj()

int trans_invtrans_adj

(

struct InvTransAdj_t *

invtrans_adj

)

Adjoint of the Inverse spectral transform (from grid-point spectral)

A InvTransAdj_t struct, initialised with new_invtrans_adj(), groups all arguments

Parameters

invtrans_adj

InvTransAdj_t struct, containing all arguments.

Usage:

• Transform of scalars

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * nscalar*trans.ngptot );
   
  // Adjoint of Inverse Transform
  struct InvTransAdj_t invtrans_adj = new_invtrans_adj(&trans);
    invtrans_adj.nscalar   = nscalar;    // input
    invtrans_adj.rspscalar = rspscalar;  // output
    invtrans_adj.rgp       = rgp;        // input
  trans_invtrans_adj(&invtrans_adj);

• Adjoint of Transform vorticity and divergence to U and V

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * 2*nvordiv*trans.ngptot );
   
  // Adjoint of Inverse Transform
  struct InvTransAdj_t invtrans_adj = new_invtrans_adj(&trans);
    invtrans_adj.nvordiv   = nvordiv;    // input
    invtrans_adj.rspvor    = rspvor;     // output
    invtrans_adj.rspdiv    = rspdiv;     // output
    invtrans_adj.rgp       = rgp;        // input  --  order: u, v
  trans_invtrans_adj(&invtrans_adj);

• Adjoint of Transform of vorticity, divergence and scalars to U, V, scalars

  struct Trans_t trans;
  trans_new(&trans);
  ... // Missing setup of trans
  double* rspscalar = malloc( sizeof(double) * nscalar*trans.nspec2 );
  double* rspvor    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rspdiv    = malloc( sizeof(double) * nvordiv*trans.nspec2 );
  double* rgp       = malloc( sizeof(double) * (2*nvordiv+nscalar)*trans.ngptot );
   
  // Adjoint of Inverse Transform
  struct InvTransAdj_t invtrans_adj = new_invtrans_adj(&trans);
    invtrans_adj.nscalar   = nscalar;    // input
    invtrans_adj.nvordiv   = nvordiv;    // input
    invtrans_adj.rspscalar = rspscalar;  // input
    invtrans_adj.rspvor    = rspvor;     // input
    invtrans_adj.rspdiv    = rspdiv;     // input
    invtrans_adj.rgp       = rgp;        // output  --  order: u, v, scalars
  trans_invtrans_adj(&invtrans_adj);

Note

trans_invtrans_adj works on distributed arrays

trans_new()

int trans_new

(

struct Trans_t *

trans

)

Constructor for Trans_t, setting default values.

Returns

Trans_t struct to be used as argument for trans_setup()

trans_set_handles_limit()

int trans_set_handles_limit

(

int

limit

)

Set limit on maximum simultaneously allocated transforms.

Note

Advanced feature

Default value is 10 This function needs to be called before trans_init() or trans_setup(), and ONLY if the default value needs to be changed.

trans_set_nprtrv()

int trans_set_nprtrv

(

int

nprtrv

)

Set nprtrv for parallel distribution of fields in spectral space.

Note

Advanced feature

Default value of nprtrv is 1, meaning that there is no parallel distribution of the same wave number for different fields (or levels) This function needs to be called before trans_init() or trans_setup(), and ONLY if the default value needs to be changed.

trans_set_radius()

int trans_set_radius

(

double

radius

)

Set radius of planet used in trans.

Note

Advanced feature

Default value of radius is Earth's radius (6371.22e+03) This function needs to be called before trans_init() or trans_setup(), and ONLY if the default value needs to be changed.

trans_set_resol()

int trans_set_resol	(	struct Trans_t *	trans,
		int	ndgl,
		const int *	nloen )

Set gridpoint resolution for trans.

Parameters

trans	[in] Trans_t used to setup
ndgl	[in] Number of lattitudes
nloen	[in] Number of longitude points for each latitude DIMENSIONS(1:NDGL)

trans_set_resol_lonlat()

int trans_set_resol_lonlat	(	struct Trans_t *	trans,
		int	nlon,
		int	nlat )

Set gridpoint resolution for trans for longitude-latitude grids.

Parameters

trans	[in] Trans_t used to setup
nlon	[in] Number of longitudes
nlat	[in] Number of latitudes (pole to pole)

• If nlat is odd, the grid must includes poles and equator
• If nlat is even, the grid must be its dual (excluding pole and equator), so points are shifted with 0.5*dx and 0.5*dy

trans_set_trunc()

int trans_set_trunc	(	struct Trans_t *	trans,
		int	nsmax )

Set spectral truncation wave number for trans.

Parameters

trans	[in] Trans_t used to setup
nsmax	[in] Spectral truncation wave number

trans_setup()

int trans_setup

(

struct Trans_t *

trans

)

Setup a new resolution to be used in the trans library.

Parameters

trans

Trans_t struct, that needs to have following variables defined: ndgl – number of lattitudes nloen – number of longitudes for each lattitude nsmax – spectral truncation wave number

All scalar values in the struct will be filled in. Remaining array values will be deallocated and set to null. To define array values, make individual calls to trans_inquire()

Usage:

struct Trans_t trans;
trans_new(&trans);
trans.ndgl  = ... ;
trans.nloen = malloc( sizeof(int)*trans.ndgl );
... // Read in or compute nloen values
trans.nsmax = (2*trans.ndgl-1)/2; // For typical linear grid
trans_setup(&trans);

Note

If trans_init() was not called beforehand, it will be called internally

trans_specnorm()

int trans_specnorm

(

struct SpecNorm_t *

specnorm

)

Compute global spectral norms.

Usage:< >

int nfld = 1;
double* rspec = malloc( sizeof(double) * nfld*trans.nspec2 );
double* rnorm = malloc( sizeof(double) * nfld );
... // load data in rspec[nspec2][nfld]
 
struct SpecNorm_t specnorm = new_specnorm(&trans);
  specnorm.rspec = rspec;
  specnorm.rnorm = rnorm;
  specnorm.nfld  = nfld;
trans_specnorm(specnorm);

trans_use_mpi()

int trans_use_mpi

(

_bool

)

Use MPI in trans library.

Note

Advanced feature

By default, MPI is used if MPI was detected during compilation. To force not to use MPI, this function may be used.

trans_vordiv_to_UV()

int trans_vordiv_to_UV

(

struct VorDivToUV_t *

vordiv_to_UV

)

Convert Spectral vorticity & divergence to Spectral u*cos(theta) & v*cos(theta)

Usage:

// We have some global spectral fields for vorticity,divergence,u*cos(theta),v*cos(theta)
int nfld = 1;
double* rspvor = malloc( sizeof(double) * nfld*ncoeff );
double* rspdiv = malloc( sizeof(double) * nfld*ncoeff );
double* rspu   = malloc( sizeof(double) * nfld*ncoeff );
double* rspv   = malloc( sizeof(double) * nfld*ncoeff );
... // load data in rspvor[ncoeff][nfld]
... // load data in rspdiv[ncoeff][nfld]
 
struct VorDivToUV_t vordiv_to_UV = new_vordiv_to_UV();
  vordiv_to_UV.rspvor = rspvor;
  vordiv_to_UV.rspdiv = rspdiv;
  vordiv_to_UV.rspu   = rspu;
  vordiv_to_UV rspv   = rspv;
  vordiv_to_UV.nfld   = nfld;
  vordiv_to_UV.ncoeff = ncoeff;
  vordiv_to_UV.nsmax  = nsmax;
trans_vordiv_to_UV(&vordiv_to_UV);

Note

• nfld indicates the multiplicity for each variable seperately
• ncoeff is equivalent to trans.nspec2 for distributed, and trans.nspec2g for global fields
• nsmax indicates the spectral truncation T.