special_interp.cc File Reference

Interpolation routines for special purposes. More...

#include <cmath>
#include <iostream>
#include <stdexcept>
#include "check_input.h"
#include "interpolation.h"
#include "math_funcs.h"
#include "messages.h"
#include "special_interp.h"

Include dependency graph for special_interp.cc:

Go to the source code of this file.

Functions

void fix_gridpos_at_boundary (ArrayOfGridPos &gp, const Index grid_size)

fix_gridpos_at_boundary

void interp_atmfield_gp2itw (Matrix &itw, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)

interp_atmfield_gp2itw

void interp_atmfield_by_itw (VectorView x, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon, ConstMatrixView itw)

interp_atmfield_by_itw

void interp_atmfield_by_gp (VectorView x, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)

interp_atmfield_by_gp

Numeric interp_atmfield_by_gp (const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const GridPos &gp_p, const GridPos &gp_lat, const GridPos &gp_lon)

interp_atmfield_by_gp

void interp_atmsurface_gp2itw (Matrix &itw, const Index &atmosphere_dim, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)

interp_atmsurface_gp2itw

void interp_atmsurface_by_itw (VectorView x, const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon, ConstMatrixView itw)

interp_atmsurface_by_itw

void interp_atmsurface_by_gp (VectorView x, const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)

interp_atmsurface_by_gp

Numeric interp_atmsurface_by_gp (const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const GridPos &gp_lat, const GridPos &gp_lon)

interp_atmsurface_by_gp

void interp_gfield3 (Numeric &value, const GField3 &gfield3, const Index &effective_dim, const Numeric &x, const Numeric &y, const Numeric &z, const String &dim0, const String &dim1, const String &dim2)

interp_gfield3

void itw2p (VectorView p_values, ConstVectorView p_grid, const ArrayOfGridPos &gp, ConstMatrixView itw)

itw2p

void p2gridpos (ArrayOfGridPos &gp, ConstVectorView old_pgrid, ConstVectorView new_pgrid, const Numeric &extpolfac)

p2gridpos

void z_at_lat_2d (VectorView z, ConstVectorView p_grid, ConstVectorView lat_grid, ConstMatrixView z_field, const GridPos &gp_lat)

z_at_lat_2d

void z_at_latlon (VectorView z, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View z_field, const GridPos &gp_lat, const GridPos &gp_lon)

z_at_latlon

Detailed Description

Interpolation routines for special purposes.

Author:: Patrick Eriksson <Patrick.Eriksson@rss.chalmers.se>

Date:: 2002-11-14

This file contains functions connected to interpolation of non-general character. The total general interpolation routines are found in interpolation.cc.

Interpolation of atmospheric fields and surfaces:

These interpolation functions interpolates a field or a surface to a set of points, such as the points of a propagation path. That is, "blue" interpolation. The functions assume that the grid positions are at hand. If several atmospheric fields shall be interpolated, the functions to use are *interp_atmfield_gp2itw* and interp_atmfield_by_itw*, where the first function is called once and the second is called for each field to be interpolated. If only one field shall be interpolated, the function interp_atmfield_by_gp* is a shortcut for calling both functions above. The exists an identical set of functions for interpolating surfaces, with names where _atmfield_ is replaced with _atmsurface_.

Possible atmospheric surfaces are *r_geoid*, *z_ground* and one page of *z_field*.

Conversion of geometric altitudes to pressure values:

To convert a geometric altitude to a pressure results in an interpolation of the pressure grid, or more exactly the log of the p_grid*. Such functions are placed in this file for that reason. These functions have names ending with "2p", for example itw2p.

Various functions connected to the atmospheric fields:

See below to find what functions that exist.

Definition in file special_interp.cc.

Function Documentation

void fix_gridpos_at_boundary	(	ArrayOfGridPos &	gp,
		const Index	grid_size
	)

fix_gridpos_at_boundary

This function fixes grid positions on the boundaries of the grids, on which one wants to interpolate.

The use of the function can be demonstrated using an example, the interpolation of the *pnd_field* on a propagation path inside the cloudbox. The gridpositions calculated in the ppath_agenda are given with respect to the atmospheric grids (p_grid, lat_grid, lon_grid), whereas the pnd_field* is defined on a subset of these grids, only inside the cloudbox. Hence the gridpositions need to be transformed. If a point is exactly at the lower boundary of the cloudbox, the gridposition index can be either cloudbox_limits[0] or cloudbox_limits[0]-1, depending on random numerical errors. To transform the gridpositions, cloudbox_limits[0] is substracted from the original gridposition index, which results in a new gridpostion index of -1. This is of coarse not allowed in the interpolation routines.

A more precise example: If a point is exactly on the lower boundary (say p-index = 12) of cloudbox the gridpositions can be gp.idx = 12, gp.fd[0] = 1, gp.fd[1] = 0 or gp.idx = 11, gp.fd[0] = 0, gp.fd[1] = 1 In the second case gp_cloud.idx will be -1 which gives an error.

Parameters:

	gp	An array of gridpositions
	grid_size	Length of the data grid

Author:: Claudia Emde

Date:: 2005-05-27

Definition at line 108 of file special_interp.cc.

References abs, Array< base >::nelem(), and out1.

Referenced by cloud_atm_vars_by_gp(), and cloud_ppath_update3D().

Numeric interp_atmfield_by_gp	(	const Index &	atmosphere_dim,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstTensor3View	x_field,
		const GridPos &	gp_p,
		const GridPos &	gp_lat,
		const GridPos &	gp_lon
	)

interp_atmfield_by_gp

As the function above but return-numeric version.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 340 of file special_interp.cc.

References gridpos_copy(), and interp_atmfield_by_gp().

void interp_atmfield_by_gp	(	VectorView	x,
		const Index &	atmosphere_dim,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstTensor3View	x_field,
		const ArrayOfGridPos &	gp_p,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon
	)

interp_atmfield_by_gp

Interpolates an atmospheric field given the grid positions.

The function performs the interpolation for a number of positions. The return variable (x) is accordingly a vector. The vector must be set to have the same length as the grid position arrays before calling the function.

The input atmospheric field is checked to be consistent with the atmosphere_dim*, *p_grid*, *lat_grid* and *lon_grid*. The length of the grid position arrays are asserted to be the identical, or for dimensions not used, that the length is zero.

Parameters:

	x	Output: Values obtained by the interpolation.
	atmosphere_dim	As the WSV with the same name.
	p_grid	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	x_field	The atmospheric field to be interpolated.
	gp_p	Pressure grid positions.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 311 of file special_interp.cc.

References interp_atmfield_by_itw(), and interp_atmfield_gp2itw().

Referenced by interp_atmfield_by_gp(), InterpAtmFieldToRteGps(), and mcPathTraceIPA().

void interp_atmfield_by_itw	(	VectorView	x,
		const Index &	atmosphere_dim,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstTensor3View	x_field,
		const ArrayOfGridPos &	gp_p,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon,
		ConstMatrixView	itw
	)

interp_atmfield_by_itw

Interpolates an atmospheric field with pre-calculated weights by interp_atmfield_gp2itw.

The function performs the interpolation for a number of positions. The return variable (x) is accordingly a vector. The vector must be set to have the same length as the grid position arrays before calling the function.

The input atmospheric field is checked to be consistent with the atmosphere_dim*, *p_grid*, *lat_grid* and *lon_grid*. The length of the grid position arrays are asserted to be the identical, or for dimensions not used, that the length is zero.

Parameters:

	x	Output: Values obtained by the interpolation.
	atmosphere_dim	As the WSV with the same name.
	p_grid	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	x_field	The atmospheric field to be interpolated.
	gp_p	Pressure grid positions.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.
	itw	Interpolation weights from interp_atmfield_gp2itw.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 246 of file special_interp.cc.

References chk_atm_field(), interp(), joker, ConstMatrixView::ncols(), Array< base >::nelem(), and ConstVectorView::nelem().

Referenced by clear_rt_vars_at_gp(), cloud_atm_vars_by_gp(), interp_atmfield_by_gp(), iy_calc(), and opt_depth_calc().

void interp_atmfield_gp2itw	(	Matrix &	itw,
		const Index &	atmosphere_dim,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		const ArrayOfGridPos &	gp_p,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon
	)

interp_atmfield_gp2itw

Converts atmospheric grid positions to weights for interpolation of an atmospheric field.

The function is intended for "blue" interpolation, that is, interpolation for a set of positions.

The output matrix for interpolation weights are resized inside the function.

The input atmospheric grids are checked to be consistent.

Parameters:

	itw	Output: Interpolation weights.
	atmosphere_dim	As the WSV with the same name.
	p_grid	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	gp_p	Pressure grid positions.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 178 of file special_interp.cc.

References chk_atm_grids(), interpweights(), Array< base >::nelem(), and Matrix::resize().

Referenced by clear_rt_vars_at_gp(), cloud_atm_vars_by_gp(), interp_atmfield_by_gp(), iy_calc(), and opt_depth_calc().

Numeric interp_atmsurface_by_gp	(	const Index &	atmosphere_dim,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstMatrixView	x_surface,
		const GridPos &	gp_lat,
		const GridPos &	gp_lon
	)

interp_atmsurface_by_gp

As the function above, but return-numeric version.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 543 of file special_interp.cc.

References gridpos_copy(), and interp_atmsurface_by_gp().

void interp_atmsurface_by_gp	(	VectorView	x,
		const Index &	atmosphere_dim,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstMatrixView	x_surface,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon
	)

interp_atmsurface_by_gp

Interpolates an atmospheric surface given the grid positions.

The function performs the interpolation for a number of positions. The return variable (x) is accordingly a vector. The vector must be set to have the same length as the grid position arrays before calling the function.

The input atmospheric surface is checked to be consistent with the atmosphere_dim*, *lat_grid* and *lon_grid*. The length of the grid position arrays are asserted to be the identical, or for dimensions not used, that the length is zero.

Parameters:

	x	Output: Values obtained by the interpolation.
	atmosphere_dim	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	x_surface	The atmospheric field to be interpolated.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 517 of file special_interp.cc.

References interp_atmsurface_by_itw(), and interp_atmsurface_gp2itw().

Referenced by interp_atmsurface_by_gp(), and InterpSurfaceFieldToRteGps().

void interp_atmsurface_by_itw	(	VectorView	x,
		const Index &	atmosphere_dim,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstMatrixView	x_surface,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon,
		ConstMatrixView	itw
	)

interp_atmsurface_by_itw

Interpolates an atmospheric surface with pre-calculated weights by interp_atmsurface_gp2itw.

The function performs the interpolation for a number of positions. The return variable (x) is accordingly a vector. The vector must be set to have the same length as the grid position arrays before calling the function.

The input atmospheric surface is checked to be consistent with the atmosphere_dim*, *lat_grid* and *lon_grid*. The length of the grid position arrays are asserted to be the identical, or for dimensions not used, that the length is zero.

Parameters:

	x	Output: Values obtained by the interpolation.
	atmosphere_dim	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	x_surface	The atmospheric field to be interpolated.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.
	itw	Interpolation weights from interp_atmsurface_gp2itw.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 455 of file special_interp.cc.

References chk_atm_surface(), interp(), joker, ConstMatrixView::ncols(), Array< base >::nelem(), and ConstVectorView::nelem().

Referenced by interp_atmsurface_by_gp().

void interp_atmsurface_gp2itw	(	Matrix &	itw,
		const Index &	atmosphere_dim,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon
	)

interp_atmsurface_gp2itw

Converts atmospheric grid positions to weights for interpolation of an atmospheric surface.

The function is intended for "blue" interpolation, that is, interpolation for a set of positions.

The output matrix for interpolation weights are resized inside the function.

The input atmospheric grids are checked to be consistent.

Parameters:

	itw	Output: Interpolation weights.
	atmosphere_dim	As the WSV with the same name.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 397 of file special_interp.cc.

References interpweights(), Array< base >::nelem(), and Matrix::resize().

Referenced by interp_atmsurface_by_gp().

void interp_gfield3	(	Numeric &	value,
		const GField3 &	gfield3,
		const Index &	effective_dim,
		const Numeric &	x,
		const Numeric &	y,
		const Numeric &	z,
		const String &	dim0,
		const String &	dim1,
		const String &	dim2
	)

interp_gfield3

Single point interpolation of a GField3.

Data where not all dimensions are effectively used can be handled. For example, if the last dimension is not ysed, effective_dim* is set to 2.

"First dimension" refers to the left-most dimension.

Parameters:

	value	Output: Obtained value.
	gfield3	Field to interpolate
	effective_dim	Effective dimension of gfield. See above.
	x	First dimension position of interpolation point.
	y	Second dimension position of interpolation point.
	z	Third dimension position of interpolation point.
	dim0	Expected name of grid for first dimension
	dim1	Expected name of grid for second dimension
	dim2	Expected name of grid for third dimension

Author:: Patrick Eriksson

Date:: 2008-10-01

Definition at line 598 of file special_interp.cc.

References chk_if_in_range(), chk_if_increasing(), GField::get_grid_name(), GField::get_numeric_grid(), gridpos(), interp(), interpweights(), joker, last(), ConstTensor3View::ncols(), and ConstTensor3View::nrows().

Referenced by InterpSurfaceEmissivityFieldIncLatLon().

void itw2p	(	VectorView	p_values,
		ConstVectorView	p_grid,
		const ArrayOfGridPos &	gp,
		ConstMatrixView	itw
	)

itw2p

Converts interpolation weights to pressures.

The function takes interpolation weights calculated with respect to the vertical dimension, and determines the corresponding pressures. This function can be used when a geometrical altitude is known and the pressure for that altitude shall be determined. The interpolation weights are then calculated using the geometrical altitudes for the pressure surfaces for the position of concern.

This can be seen as a 1D "blue" interpolation. That means that the number of columns of itw shall be 2.

Parameters:

	p_values	Output: Found pressure values.
	p_grid	As the WSV with the same name.
	gp	Altitude grid positions.
	itw	Interpolation weights

Author:: Patrick Eriksson

Date:: 2002-11-13

Definition at line 780 of file special_interp.cc.

References interp(), ConstMatrixView::ncols(), ConstVectorView::nelem(), ConstMatrixView::nrows(), and transform().

Referenced by clear_rt_vars_at_gp(), cloud_atm_vars_by_gp(), cloud_ppath_update3D(), get_refr_index_1d(), get_refr_index_2d(), get_refr_index_3d(), interp_cloud_coeff1D(), iy_calc(), and opt_depth_calc().

void p2gridpos	(	ArrayOfGridPos &	gp,
		ConstVectorView	old_pgrid,
		ConstVectorView	new_pgrid,
		const Numeric &	extpolfac
	)

p2gridpos

Calculates grid positions for pressure values.

This function works as *gridpos*, but is adapted to handle pressure grids. The ARTS defintions result in that pressures shall not be interpolated directly, it is the log of the pressure that shall be interpolated. This means that if some values shall be interpolated to some given pressures, the grid positions shall be calculated with this function. The interpolation can then be performed as usual.

Parameters:

	gp	Output: Grid position Array.
	old_pgrid	The original pressure grid.
	new_pgrid	The new pressure grid.
	extpolfac	Extrapolation factor. Default value is 0.5, which means that extrapolation of half of the last grid distance is allowed. You don't have to specify this.

Author:: Patrick Eriksson

Date:: 2003-01-20

Author:: Stefan Buehler

Date:: 2008-03-03

Definition at line 827 of file special_interp.cc.

References gridpos(), ConstVectorView::nelem(), and transform().

Referenced by AtmFieldsCalc(), doit_i_fieldSetClearsky(), get_perturbation_gridpos(), jacobian_from_path_to_rgrids(), pnd_fieldCalc(), and refr_indexFieldAndGradients().

void z_at_lat_2d	(	VectorView	z,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstMatrixView	z_field,
		const GridPos &	gp_lat
	)

z_at_lat_2d

Returns the geomtrical altitudes of *p_grid* for one latitude.

The latitude is specified by its grid position, in an ArrayOfGridPos of length 1. The altitude field (*z_field*) is then interpolated to that latitude.

Parameters:

	z	Out: Found altitudes.
	p_grid	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	z_field	The pressure and latitude part of the WSV with the same name (that is, the first column).
	gp_lat	Latitude grid position.

Author:: Patrick Eriksson

Date:: 2002-11-18

Definition at line 866 of file special_interp.cc.

References gridpos(), gridpos_copy(), interp(), interpweights(), joker, and ConstVectorView::nelem().

Referenced by get_refr_index_2d(), ppath_start_stepping(), and refr_indexFieldAndGradients().

void z_at_latlon	(	VectorView	z,
		ConstVectorView	p_grid,
		ConstVectorView	lat_grid,
		ConstVectorView	lon_grid,
		ConstTensor3View	z_field,
		const GridPos &	gp_lat,
		const GridPos &	gp_lon
	)

z_at_latlon

Returns the geomtrical altitudes of *p_grid* for one latitude and one longitude.

The latitude and longitude are specified by their grid position, in an ArrayOfGridPos of length 1. The altitude field (*z_field*) is then interpolated to that latitude and longitude.

Parameters:

	z	Out: Found altitudes.
	p_grid	As the WSV with the same name.
	lat_grid	As the WSV with the same name.
	lon_grid	As the WSV with the same name.
	z_field	As the WSV with the same name.
	gp_lat	Latitude grid positions.
	gp_lon	Longitude grid positions.

Author:: Patrick Eriksson

Date:: 2002-12-31

Definition at line 918 of file special_interp.cc.

References gridpos(), gridpos_copy(), interp(), interpweights(), joker, and ConstVectorView::nelem().

Referenced by cloudbox_ppath_start_stepping(), get_refr_index_3d(), mcPathTraceIPA(), ppath_start_stepping(), and refr_indexFieldAndGradients().


Functions
void	fix_gridpos_at_boundary (ArrayOfGridPos &gp, const Index grid_size)
	fix_gridpos_at_boundary
void	interp_atmfield_gp2itw (Matrix &itw, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)
	interp_atmfield_gp2itw
void	interp_atmfield_by_itw (VectorView x, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon, ConstMatrixView itw)
	interp_atmfield_by_itw
void	interp_atmfield_by_gp (VectorView x, const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)
	interp_atmfield_by_gp
Numeric	interp_atmfield_by_gp (const Index &atmosphere_dim, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View x_field, const GridPos &gp_p, const GridPos &gp_lat, const GridPos &gp_lon)
	interp_atmfield_by_gp
void	interp_atmsurface_gp2itw (Matrix &itw, const Index &atmosphere_dim, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)
	interp_atmsurface_gp2itw
void	interp_atmsurface_by_itw (VectorView x, const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon, ConstMatrixView itw)
	interp_atmsurface_by_itw
void	interp_atmsurface_by_gp (VectorView x, const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon)
	interp_atmsurface_by_gp
Numeric	interp_atmsurface_by_gp (const Index &atmosphere_dim, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstMatrixView x_surface, const GridPos &gp_lat, const GridPos &gp_lon)
	interp_atmsurface_by_gp
void	interp_gfield3 (Numeric &value, const GField3 &gfield3, const Index &effective_dim, const Numeric &x, const Numeric &y, const Numeric &z, const String &dim0, const String &dim1, const String &dim2)
	interp_gfield3
void	itw2p (VectorView p_values, ConstVectorView p_grid, const ArrayOfGridPos &gp, ConstMatrixView itw)
	itw2p
void	p2gridpos (ArrayOfGridPos &gp, ConstVectorView old_pgrid, ConstVectorView new_pgrid, const Numeric &extpolfac)
	p2gridpos
void	z_at_lat_2d (VectorView z, ConstVectorView p_grid, ConstVectorView lat_grid, ConstMatrixView z_field, const GridPos &gp_lat)
	z_at_lat_2d
void	z_at_latlon (VectorView z, ConstVectorView p_grid, ConstVectorView lat_grid, ConstVectorView lon_grid, ConstTensor3View z_field, const GridPos &gp_lat, const GridPos &gp_lon)
	z_at_latlon