This is a base class that contains common attributes and virtual declarations for higher level objects that are derived from this base.

Note that both 2d and 3d grid and field objects are derived from here.

Source:

gclgrid.h:81

Author:

Gary L. Pavlis

Version:

unknown

Entity	Type	Scope	Short Description
~BasicGCLgrid	destructor	public	automatically generated
BasicGCLgrid	constructor	public	Default Constructor.
BasicGCLgrid	constructor	public	undocumented
azimuth_y	attribute	public	Nominal azimuth (radians) of positive y axis of grid line at origin location.
compute_extents	method	public	This member function sets the x1min, x1max, x2min, x2max, x3min, and x3max bounding box attribute.
ctog	method	public	Convert Cartesian coordinates to geographical coordinates.
ctog	method	public	Convert from Cartesian coordinates to geographical coordinates.
dx1_nom	attribute	public	Nominal spacing (km) of grid lines along the 1 position gridlines.
dx2_nom	attribute	public	Nominal spacing (km) of grid lines along the 2 position gridlines.
fetch_transformation_matrix	method	public	Returns the transformation matrix for this grid as a 3x3 dmatrix object.
fetch_translation_vector	method	public	Returns a newly allocated 3 vector of double containing a copy of the translation vector defining the GCLgrid transformation property.
get_index	method	public	Query for the current lookup index position.
gtoc	method	public	Convert from geographical to Cartesian coordinates in the GCLgrid coordinate system.
gtoc	method	public	Convert from geographical to Cartesian coordinates in the GCLgrid coordinate system.
gtoc_rmatrix	attribute	public	This is a rotation matrix that defines the transformation from standard spherical coordinates (the geographical reference frame) to the local Cartesian coordinate system used in a GCLgrid.
i0	attribute	public	Offset in first index to origin grid point.
j0	attribute	public	Offset in second index to origin grid point.
lat0	attribute	public	Latitude (radians) of origin of the grid's Cartesian coordinate system.
lon0	attribute	public	Longitude (radians) of origin of the grid's Cartesian coordinate system.
n1	attribute	public	Number of grid points in generalized coordinate index 1 direction (first array index).
n2	attribute	public	Number of grid points in generalized coordinate index 2 direction (second array index).
name	attribute	public	Name assigned to this object
operator !=	operator	public	Comparison of two grids for inequality.
operator =	operator	public	automatically generated
operator ==	operator	public	Comparison of two grids for equality.
r0	attribute	public	Radial distance of origin of the grid's Cartesian coordinate system from Earth's center.
reset_index	method	public	Reset lookup index to origin.
set_transformation_matrix	method	public	Set or reset the transformation properties for the grid.
translation_vector	attribute	public	This is a close companion to the gtoc_rmatrix.
x1high	attribute	public	Cartesian x1 coordinate of upper limit of bounding box for grid.
x1low	attribute	public	Cartesian x1 coordinate of lower limit of bounding box for grid.
x2high	attribute	public	Cartesian x2 coordinate of upper limit of bounding box for grid.
x2low	attribute	public	Cartesian x2 coordinate of lower limit of bounding box for grid.
x3high	attribute	public	Cartesian x3 coordinate of upper limit of bounding box for grid.
x3low	attribute	public	Cartesian x3 coordinate of lower limit of bounding box for grid.

automatically generated

Source:

gclgrid.h

Code:

public ~ BasicGCLgrid ( )

Default Constructor.

Implemented to initialize all base attributes explicitly.

Source:

gclgrid.h:163

Code:

public BasicGCLgrid (

)

undocumented

Source:

gclgrid.h:165

Code:

public BasicGCLgrid (

const BasicGCLgrid & old )

Nominal azimuth (radians) of positive y axis of grid line at origin location.

Source:

gclgrid.h:102

Code:

public double azimuth_y

This member function sets the x1min, x1max, x2min, x2max, x3min, and x3max bounding box attribute.

These define the "extents" of the name. Should be needed only if one builds a custom grid from user defined coordinates. Said a different way if you build a GCLgrid from lower level routines be sure to call this function to set the bounding box correctly.

Source:

gclgrid.h:240

Code:

public virtual void compute_extents (

) = 0

Convert Cartesian coordinates to geographical coordinates.

Source:

gclgrid.h:208

Params:

x1p	- Cartesian x1 coordinate of point to convert
x2p	- Cartesian x2 coordinate of point to convert
x3p	- Cartesian x3 coordinate of point to convert

Returns:

Geographic_point data structure (see Geographic_point )

Code:

public Geographic_point ctog (	double x1p ,
	double x2p ,
	double x3p )

Convert from Cartesian coordinates to geographical coordinates.

Source:

gclgrid.h:214

Param:

p	point to convert stored in a Cartesian_point data structure

Returns:

Geographic_point data structure (see Geographic_point )

Code:

public Geographic_point ctog (

Cartesian_point p )

Nominal spacing (km) of grid lines along the 1 position gridlines.

Source:

gclgrid.h:106

Code:

public double dx1_nom

Nominal spacing (km) of grid lines along the 2 position gridlines.

Source:

gclgrid.h:111

Code:

public double dx2_nom

Returns the transformation matrix for this grid as a 3x3 dmatrix object.

Source:

gclgrid.h:194

Code:

public dmatrix fetch_transformation_matrix (

)

Returns a newly allocated 3 vector of double containing a copy of the translation vector defining the GCLgrid transformation property.

The user must be sure to call delete [] after using this vector to avoid a memory leak.

Source:

gclgrid.h:200

Code:

public double * fetch_translation_vector (

)

Query for the current lookup index position.

The lookup functions used in the GCLgrid library keep and index of the previous lookup result under an assumption that the next point requested will be nearby. This method is used to ask what the current index position.

Source:

gclgrid.h:259

Param:

ind	vector of ints of length sufficient to hold the index (2 for 2d and 3 for 3d grids)

Code:

public virtual void get_index (

int * ind ) = 0

Convert from geographical to Cartesian coordinates in the GCLgrid coordinate system.

Source:

gclgrid.h:224

Params:

plat	Latitude (radians) of point to convert.
plon	Longitude (radians) of point to convert.
pr	Earth radius (km) of point to convert.

Returns:

Cartesian_point data structure (see @endlink)

Code:

public Cartesian_point gtoc (	double plat ,
	double plon ,
	double pr )

Convert from geographical to Cartesian coordinates in the GCLgrid coordinate system.

Source:

gclgrid.h:232

Param:

p	point to convert stored in a @link Geographic_point @endlink data structure.

Returns:

Cartesian_point data structure (see @endlink)

Code:

public Cartesian_point gtoc (

Geographic_point p )

This is a rotation matrix that defines the transformation from standard spherical coordinates (the geographical reference frame) to the local Cartesian coordinate system used in a GCLgrid.

Was private in an earlier incarnation, but this is is messy when we depend on inheritance so it is public. Users should not manipulate this directly, however, but if it is desired they should use the fetch_transformation_matrix member function.

Source:

gclgrid.h:174

Code:

public double gtoc_rmatrix [ 3 ] [ 3 ]

Offset in first index to origin grid point.

i.e. origin is at first coordinate index i0.

Source:

gclgrid.h:123

Code:

public int i0

Offset in second index to origin grid point.

i.e. origin is at second coordinate index j0. ([i0][j0])

Source:

gclgrid.h:127

Code:

public int j0

Latitude (radians) of origin of the grid's Cartesian coordinate system.

Source:

gclgrid.h:90

Code:

public double lat0

Longitude (radians) of origin of the grid's Cartesian coordinate system.

Source:

gclgrid.h:94

Code:

public double lon0

Number of grid points in generalized coordinate index 1 direction (first array index).

Source:

gclgrid.h:115

Code:

public int n1

Number of grid points in generalized coordinate index 2 direction (second array index).

Source:

gclgrid.h:119

Code:

public int n2

Name assigned to this object

Source:

gclgrid.h:86

Code:

public string name

Comparison of two grids for inequality.

Equality in this context is NOT the obvious. Equality means the transformation properties of the two grids being compared are the same. That is, the operator tests only the transformation matrix and translation vector for equality. This is a necessary condition to allow to grids to be mapped onto each other for higher level operations like +=. Returns true if the transformation properties of two matrices do not match.

Source:

gclgrid.h:276

Code:

public bool operator != (

const BasicGCLgrid & )

automatically generated

Source:

gclgrid.h

Code:

public BasicGCLgrid & operator = (

const BasicGCLgrid & )

Comparison of two grids for equality.

Equality in this context is NOT the obvious. Equality means the transformation properties of the two grids being compared are the same. That is, the operator tests only the transformation matrix and translation vector for equality. This is a necessary condition to allow to grids to be mapped onto each other for higher level operations like +=.

Source:

gclgrid.h:267

Code:

public bool operator == (

const BasicGCLgrid & )

Radial distance of origin of the grid's Cartesian coordinate system from Earth's center.

Source:

gclgrid.h:98

Code:

public double r0

Reset lookup index to origin.

The lookup functions used in the GCLgrid library keeps an index of the previous lookup results under an assumption the next point requested will be nearby. This can cause convergence problems in some grids, however, if that position is a poor place to start (e.g. sudden jump to a completely different location). This function should be called if a lookup fails to try to recover. Internal methods like the += operator does this automatically.

Source:

gclgrid.h:251

Code:

public virtual void reset_index (

) = 0

Set or reset the transformation properties for the grid.

The transformation properties are uniquely defined by the coordinate system origin and azimuth_y so if these are all that are known this low level member function can be called to set the transformation properties. It is of minimal use to most users and should be used cautiously and only if you thoroughly understand the way this all works.

Source:

gclgrid.h:190

Code:

public void set_transformation_matrix (

)

This is a close companion to the gtoc_rmatrix.

The full transformation used to define the Cartesian system in a GCLgrid is a translation from the earth's center to the grid coordinate system origin. This is followed by a rotation by gtoc_rmatrix. The translation_vector attribute defines what the name implies.

Source:

gclgrid.h:181

Code:

public double translation_vector [ 3 ]

Cartesian x1 coordinate of upper limit of bounding box for grid.

This edge of the bounding box is defined as the largest x1 value plus dx1_nom.

Source:

gclgrid.h:137

Code:

public double x1high

Cartesian x1 coordinate of lower limit of bounding box for grid.

This edge of the bounding box is defined as the smallest x1 value minus dx1_nom.

Source:

gclgrid.h:132

Code:

public double x1low

Cartesian x2 coordinate of upper limit of bounding box for grid.

This edge of the bounding box is defined as the largest x2 value plus dx2_nom.

Source:

gclgrid.h:147

Code:

public double x2high

Cartesian x2 coordinate of lower limit of bounding box for grid.

This edge of the bounding box is defined as the smallest x2 value minus dx2_nom.

Source:

gclgrid.h:142

Code:

public double x2low

Cartesian x3 coordinate of upper limit of bounding box for grid.

This edge of the bounding box is defined as the largest x3 value plus dx3_nom.

Source:

gclgrid.h:157

Code:

public double x3high

Cartesian x3 coordinate of lower limit of bounding box for grid.

This edge of the bounding box is defined as the smallest x3 value minus dx3_nom.

Source:

gclgrid.h:152

Code:

public double x3low