montecarlo.cc File Reference

functions used by MCGeneral More...

#include <cfloat>
#include <sstream>
#include "auto_md.h"
#include "geodetic.h"
#include "mc_interp.h"
#include "montecarlo.h"

Go to the source code of this file.

Functions
Numeric	ext_I (const Numeric &I, const Numeric &Q, const Numeric &kI, const Numeric &kQ, const Numeric &s)
	ext_I. More...
void	brent_zero (Numeric &sb, const Numeric &a, const Numeric &b, const Numeric &t, const Numeric &rn, const Numeric &I, const Numeric &Q, const Numeric &KI, const Numeric &KQ)
	brent_zero. More...
void	clear_rt_vars_at_gp (Workspace &ws, MatrixView ext_mat_mono, VectorView abs_vec_mono, Numeric &temperature, const Agenda &propmat_clearsky_agenda, const Numeric &f_mono, const GridPos &gp_p, const GridPos &gp_lat, const GridPos &gp_lon, ConstVectorView p_grid, ConstTensor3View t_field, ConstTensor4View vmr_field)
	clear_rt_vars_at_gp. More...
void	cloudy_rt_vars_at_gp (Workspace &ws, MatrixView ext_mat_mono, VectorView abs_vec_mono, VectorView pnd_vec, Numeric &temperature, const Agenda &propmat_clearsky_agenda, const Index stokes_dim, const Index f_index, const Vector &f_grid, const GridPos &gp_p, const GridPos &gp_lat, const GridPos &gp_lon, ConstVectorView p_grid_cloud, ConstTensor3View t_field_cloud, ConstTensor4View vmr_field_cloud, const Tensor4 &pnd_field, const ArrayOfArrayOfSingleScatteringData &scat_data, const ArrayOfIndex &cloudbox_limits, const Vector &rte_los)
	cloudy_rt_vars_at_gp. More...
void	cloud_atm_vars_by_gp (VectorView pressure, VectorView temperature, MatrixView vmr, MatrixView pnd, const ArrayOfGridPos &gp_p, const ArrayOfGridPos &gp_lat, const ArrayOfGridPos &gp_lon, const ArrayOfIndex &cloudbox_limits, ConstVectorView p_grid_cloud, ConstTensor3View t_field_cloud, ConstTensor4View vmr_field_cloud, ConstTensor4View pnd_field)
	cloud_atm_vars_by_gp. More...
void	get_ppath_transmat (Workspace &ws, MatrixView &trans_mat, const Ppath &ppath, const Agenda &propmat_clearsky_agenda, const Index stokes_dim, const Index f_index, const Vector &f_grid, const Vector &p_grid, const Tensor3 &t_field, const Tensor4 &vmr_field, const ArrayOfIndex &cloudbox_limits, const Tensor4 &pnd_field, const ArrayOfArrayOfSingleScatteringData &scat_data, const Verbosity &verbosity)
	get_ppath_transmat. More...
bool	is_anyptype_nonTotRan (const ArrayOfArrayOfSingleScatteringData &scat_data)
	is_anyptype_nonTotRan. More...
void	mcPathTraceGeneral (Workspace &ws, MatrixView evol_op, Vector &abs_vec_mono, Numeric &temperature, MatrixView ext_mat_mono, Rng &rng, Vector &rte_pos, Vector &rte_los, Vector &pnd_vec, Numeric &g, Ppath &ppath_step, Index &termination_flag, bool &inside_cloud, const Agenda &ppath_step_agenda, const Numeric &ppath_lmax, const Numeric &ppath_lraytrace, const Numeric &taustep_limit, const Agenda &propmat_clearsky_agenda, const Index stokes_dim, const Index f_index, const Vector &f_grid, const Vector &p_grid, const Vector &lat_grid, const Vector &lon_grid, const Tensor3 &z_field, const Vector &refellipsoid, const Matrix &z_surface, const Tensor3 &t_field, const Tensor4 &vmr_field, const ArrayOfIndex &cloudbox_limits, const Tensor4 &pnd_field, const ArrayOfArrayOfSingleScatteringData &scat_data, const Verbosity &verbosity)
	mcPathTraceGeneral. More...
void	mcPathTraceRadar (Workspace &ws, MatrixView evol_op, Vector &abs_vec_mono, Numeric &temperature, MatrixView ext_mat_mono, Rng &rng, Vector &rte_pos, Vector &rte_los, Vector &pnd_vec, Numeric &stot, Numeric &ttot, Ppath &ppath_step, Index &termination_flag, bool &inside_cloud, const Agenda &ppath_step_agenda, const Numeric &ppath_lmax, const Numeric &ppath_lraytrace, const Agenda &propmat_clearsky_agenda, const bool &anyptype_nonTotRan, const Index stokes_dim, const Index f_index, const Vector &f_grid, const Vector &Iprop, const Vector &p_grid, const Vector &lat_grid, const Vector &lon_grid, const Tensor3 &z_field, const Vector &refellipsoid, const Matrix &z_surface, const Tensor3 &t_field, const Tensor4 &vmr_field, const ArrayOfIndex &cloudbox_limits, const Tensor4 &pnd_field, const ArrayOfArrayOfSingleScatteringData &scat_data, const Verbosity &verbosity)
	mcPathTraceRadar. More...
void	Sample_los (VectorView new_rte_los, Numeric &g_los_csc_theta, MatrixView Z, Rng &rng, ConstVectorView rte_los, const ArrayOfArrayOfSingleScatteringData &scat_data, const Index f_index, const Index stokes_dim, ConstVectorView pnd_vec, ConstVectorView Z11maxvector, const Numeric Csca, const Numeric rtp_temperature, const Index t_interp_order)
	Sample_los. More...
void	Sample_los_uniform (VectorView new_rte_los, Rng &rng)
	Sample_los_uniform. More...

Variables
const Numeric	SPEED_OF_LIGHT

Detailed Description

functions used by MCGeneral

Author

Cory Davis cory@.nosp@m.met..nosp@m.ed.ac.nosp@m..uk

Date

2003-06-19

Author

Cory Davis cory@.nosp@m.met..nosp@m.ed.ac.nosp@m..uk

Date

2003-06-19

FIXMEDOC ***: mcPathTraceRadar, opt_propExtract, Sample_los_uniform (JUST author) cloudy_rt_vars_at_gp (JUST DATE CHECK), clear_rt_vars_at_gp(JUST DATE CHECK). FIXMEDOC ***: In .cc some root-finding helper functions (for MCRadar) that don't need visibility outside .cc, meaning that are not in .h JUST CLARIFICATION => brent_zero, ext_I. Further docomentation ???

Definition in file montecarlo.cc.

Function Documentation

brent_zero()

void brent_zero	(	Numeric &	sb,
		const Numeric &	a,
		const Numeric &	b,
		const Numeric &	t,
		const Numeric &	rn,
		const Numeric &	I,
		const Numeric &	Q,
		const Numeric &	KI,
		const Numeric &	KQ
	)

brent_zero.

This function seeks the root of a function F(X) in an interval [A,B].

Discussion: The interval [A,B] must be a change of sign interval for F. That is, F(A) and F(B) must be of opposite signs. Then assuming that F is continuous implies the existence of at least one value C between A and B for which F(C) = 0.

The location of the zero is determined to within an accuracy of 6 * MACHEPS * abs ( C ) + 2 * T.

Thanks to Thomas Secretin for pointing out a transcription error in the setting of the value of P, 11 February 2013.

Modifications by Ian S. Adams, U.S. Naval Research Laboratory to conform to ARTS and to hardcode function for root finding while passing in mulitple args for function.

Licensing:

This code is distributed under the GNU LGPL license.

Modified:

11 February 2013, J. Burkardt 15 July 2016 , I. Adams

Author:

Original FORTRAN77 version by Richard Brent. C++ version by John Burkardt.

Reference:

Richard Brent, Algorithms for Minimization Without Derivatives, Dover, 2002, ISBN: 0-486-41998-3, LC: QA402.5.B74.

Parameters:

Input, double A, B, the endpoints of the change of sign interval. Input, double T, a positive error tolerance. Output, double ZERO, the estimated value of a zero of the function F.

Parameters

[out]	sb	The estimated value of a zero of the function F.
[in]	a	The lower endpoint of the change of sign interval
[in]	b	The upper endpoint of the change of sign interval
[in]	t	A positive error tolerance.
[in]	rn	A Random number.
[in]	I	1st Stokes element *** FIXMEDOC ***
[in]	Q	2nd Stokes element *** FIXMEDOC ***
[in]	KI	Extinction matrix element 0,0 *** FIXMEDOC ***
[in]	KQ	Extinction matrix element 0,1 *** FIXMEDOC ***

Author

J. Burkhardt

Date

20??-??-??

Definition at line 132 of file montecarlo.cc.

clear_rt_vars_at_gp()

void clear_rt_vars_at_gp	(	Workspace &	ws,
		MatrixView	ext_mat_mono,
		VectorView	abs_vec_mono,
		Numeric &	temperature,
		const Agenda &	propmat_clearsky_agenda,
		const Numeric &	f_mono,
		const GridPos &	gp_p,
		const GridPos &	gp_lat,
		const GridPos &	gp_lon,
		ConstVectorView	p_grid,
		ConstTensor3View	t_field,
		ConstTensor4View	vmr_field
	)

clear_rt_vars_at_gp.

Calculates a bunch of atmospheric variables at the end of a ppath.

Parameters

[in,out]	ws	Current workspace.
[out]	ext_mat_mono	Total monochromatic extinction matrix.
[out]	abs_vec_mono	Total monochromatic absorption vector.
[out]	temperature	a vector of temperatures
[in]	propmat_clearsky_agenda	As the WSA.
[in]	f_mono	Frequency (single entry vector).
[in]	gp_p	An array of pressure gridpoints.
[in]	gp_lat	An array of latitude gridpoints.
[in]	gp_lon	An array of longitude gridpoints.
[in]	p_grid	The pressure grid.
[in]	t_field	The temperature grid.
[in]	vmr_field	VMR field.

Author

Cory Davis

Date

2005-02-19? *** FIXMEDOC ***

Definition at line 244 of file montecarlo.cc.

References interp_atmfield_by_itw(), interp_atmfield_gp2itw(), interpweights(), itw2p(), joker, PropagationMatrix::MatrixAtPosition(), ns, opt_prop_sum_propmat_clearsky(), ARTS::Var::p_grid(), ARTS::Var::propmat_clearsky_agenda(), propmat_clearsky_agendaExecute(), ARTS::Var::t_field(), StokesVector::VectorAtPosition(), and ARTS::Var::vmr_field().

Referenced by get_ppath_transmat(), and mcPathTraceRadar().

cloud_atm_vars_by_gp()

void cloud_atm_vars_by_gp	(	VectorView	pressure,
		VectorView	temperature,
		MatrixView	vmr,
		MatrixView	pnd,
		const ArrayOfGridPos &	gp_p,
		const ArrayOfGridPos &	gp_lat,
		const ArrayOfGridPos &	gp_lon,
		const ArrayOfIndex &	cloudbox_limits,
		ConstVectorView	p_grid_cloud,
		ConstTensor3View	t_field_cloud,
		ConstTensor4View	vmr_field_cloud,
		ConstTensor4View	pnd_field
	)

cloud_atm_vars_by_gp.

Returns pressure, temperature, VMRs and PNDs, at points corresponding to arrays of gridpositions gp_p, gp_lat, and gp_lon. The field and grid input variables all span only the cloudbox

Parameters

[out]	pressure	A vector of pressures.
[out]	temperature	A vector of temperatures.
[out]	vmr	A n_species by n_p matrix of VMRs.
[out]	pnd	A n_scatelem by n_p matrix of PNDs.
[in]	gp_p	An array of pressure gridpoints.
[in]	gp_lat	An array of latitude gridpoints.
[in]	gp_lon	An array of longitude gridpoints.
[in]	cloudbox_limits	The limits of the cloud box.
[in]	p_grid_cloud	The subset of p_grid within the cloudbox.
[in]	t_field_cloud	The subset of t_field within the cloudbox.
[in]	vmr_field_cloud	The subset of vmr_field within the cloudbox.
[in]	pnd_field	Particle number density field.

Author

Cory Davis

Date

2005-06-07

Definition at line 459 of file montecarlo.cc.

References ARTS::Var::atmosphere_dim(), ARTS::Var::cloudbox_limits(), gridpos_upperend_check(), interp_atmfield_by_itw(), interp_atmfield_gp2itw(), interpweights(), itw2p(), joker, ConstTensor4View::nbooks(), Array< base >::nelem(), ConstVectorView::nelem(), ns, and ARTS::Var::pnd_field().

Referenced by cloudy_rt_vars_at_gp().

cloudy_rt_vars_at_gp()

void cloudy_rt_vars_at_gp	(	Workspace &	ws,
		MatrixView	ext_mat_mono,
		VectorView	abs_vec_mono,
		VectorView	pnd_vec,
		Numeric &	temperature,
		const Agenda &	propmat_clearsky_agenda,
		const Index	stokes_dim,
		const Index	f_index,
		const Vector &	f_grid,
		const GridPos &	gp_p,
		const GridPos &	gp_lat,
		const GridPos &	gp_lon,
		ConstVectorView	p_grid_cloud,
		ConstTensor3View	t_field_cloud,
		ConstTensor4View	vmr_field_cloud,
		const Tensor4 &	pnd_field,
		const ArrayOfArrayOfSingleScatteringData &	scat_data,
		const ArrayOfIndex &	cloudbox_limits,
		const Vector &	rte_los
	)

cloudy_rt_vars_at_gp.

Calculates a bunch of atmospheric variables at the end of a ppath.

Parameters

[in,out]	ws	Current workspace.
[out]	ext_mat_mono	Total monochromatic extinction matrix.
[out]	abs_vec_mono	Total monochromatic absorption vector.
[out]	pnd_vec	Vector of particle number densities (one element per scattering element).
[out]	temperature	A vector of temperatures
[in]	propmat_clearsky_agenda	Agenda calculating the absorption coefficient matrices.
[in]	stokes_dim	The dimensionality of the Stokes vector (1-4).
[in]	f_index	Index of frequency grid point handeled.
[in]	f_grid	Frequency grid for monochromatic pencil beam calculations.
[in]	gp_p	An array of pressure gridpoints.
[in]	gp_lat	An array of latitude gridpoints.
[in]	gp_lon	An array of longitude gridpoints.
[in]	p_grid_cloud	The subset of p_grid within the cloudbox.
[in]	t_field_cloud	The subset of t_field within the cloudbox.
[in]	vmr_field_cloud	The subset of vmr_field within the cloudbox.
[in]	pnd_field	Particle number density field.
[in]	scat_data	Array of single scattering data.
[in]	cloudbox_limits	The limits of the cloud box.
[in]	rte_los

Author

Cory Davis

Date

2005-02-19? *** FIXMEDOC ***

Definition at line 326 of file montecarlo.cc.

References cloud_atm_vars_by_gp(), ARTS::Var::cloudbox_limits(), ARTS::Var::f_grid(), ARTS::Var::f_index(), joker, PropagationMatrix::MatrixAtPosition(), mirror_los(), ConstTensor4View::nbooks(), ns, opt_prop_Bulk(), opt_prop_NScatElems(), opt_prop_ScatSpecBulk(), opt_prop_sum_propmat_clearsky(), ARTS::Var::pnd_field(), ARTS::Var::propmat_clearsky_agenda(), propmat_clearsky_agendaExecute(), ARTS::Var::rte_los(), ARTS::Var::scat_data(), ARTS::Var::stokes_dim(), and StokesVector::VectorAtPosition().

Referenced by get_ppath_transmat(), and mcPathTraceRadar().

ext_I()

Numeric ext_I	(	const Numeric &	I,
		const Numeric &	Q,
		const Numeric &	kI,
		const Numeric &	kQ,
		const Numeric &	s
	)

ext_I.

Calculate the extinction of I for a propagating "photon"

Parameters

[in]	I	1st Stokes element *** FIXMEDOC ***
[in]	Q	2nd Stokes element *** FIXMEDOC ***
[in]	KI	Extinction matrix element 0,0 *** FIXMEDOC ***
[in]	KQ	Extinction matrix element 0,1 *** FIXMEDOC ***
[in]	s	Pathlength *** FIXMEDOC ***

Author

Ian Adams

Date

2016-06-15

Definition at line 58 of file montecarlo.cc.

get_ppath_transmat()

void get_ppath_transmat	(	Workspace &	ws,
		MatrixView &	trans_mat,
		const Ppath &	ppath,
		const Agenda &	propmat_clearsky_agenda,
		const Index	stokes_dim,
		const Index	f_index,
		const Vector &	f_grid,
		const Vector &	p_grid,
		const Tensor3 &	t_field,
		const Tensor4 &	vmr_field,
		const ArrayOfIndex &	cloudbox_limits,
		const Tensor4 &	pnd_field,
		const ArrayOfArrayOfSingleScatteringData &	scat_data_mono,
		const Verbosity &	verbosity
	)

get_ppath_transmat.

Routine to get the transmission matrix along a pre-defined propagation path. This is based on mcPathTraceGeneral using the routines from this source file. Routines from rte.cc require wind and magnetic field data that has not been typically passed to the Monte Carlo routines.

Parameters

[in,out]	ws	Current workspace.
[out]	trans_mat	Matrix defining transmission over the ppath direction multiplied by sin(za)
[in]	ppath	Propagation path over which transmission matrix is desired
[in]	propmat_clearsky_agenda	Agenda calculating the absorption coefficient matrices.
[in]	stokes_dim	The dimensionality of the Stokes vector (1-4).
[in]	f_index	Index of frequency grid point handeled.
[in]	f_grid	Frequency grid for monochromatic pencil beam calculations.
[in]	p_grid	The pressure grid.
[in]	t_field	The temperature grid.
[in]	vmr_field	VMR field.
[in]	cloudbox_limits	The limits of the cloud box.
[in]	pnd_field	Particle number density field.
[in]	scat_data	Array of single scattering data.
[in]	verbosity	Verbosity variable to dynamically control the reporting level during runtime.

Author

Ian S. Adams

Date

2015-09-15

Definition at line 544 of file montecarlo.cc.

References clear_rt_vars_at_gp(), ARTS::Var::cloudbox_limits(), cloudy_rt_vars_at_gp(), CREATE_OUT0, ext2trans(), ARTS::Var::ext_mat(), ARTS::Var::f_grid(), ARTS::Var::f_index(), id_mat(), is_gp_inside_cloudbox(), joker, mult(), ARTS::Var::p_grid(), ARTS::Var::pnd_field(), ARTS::Var::ppath(), ARTS::Var::propmat_clearsky_agenda(), ARTS::Var::scat_data(), ARTS::Var::stokes_dim(), ARTS::Var::t_field(), and ARTS::Var::vmr_field().

is_anyptype_nonTotRan()

bool is_anyptype_nonTotRan

(

const ArrayOfArrayOfSingleScatteringData &

scat_data_mono

)

is_anyptype_nonTotRan.

Some operations in Monte Carlo simulations are different depending on the ptype of the scattering elements. This function searches scat_data to determine if any of the scattering elements have ptype=30.

Parameters

[in]

scat_data_mono

Monochromatic single scattering data.

Author

Cory Davis

Date

2004-1-31

Definition at line 694 of file montecarlo.cc.

References is_anyptype_nonTotRan(), PTYPE_TOTAL_RND, and ARTS::Var::scat_data().

Referenced by is_anyptype_nonTotRan(), and MCRadar().

mcPathTraceGeneral()

void mcPathTraceGeneral	(	Workspace &	ws,
		MatrixView	evol_op,
		Vector &	abs_vec_mono,
		Numeric &	temperature,
		MatrixView	ext_mat_mono,
		Rng &	rng,
		Vector &	rte_pos,
		Vector &	rte_los,
		Vector &	pnd_vec,
		Numeric &	g,
		Ppath &	ppath_step,
		Index &	termination_flag,
		bool &	inside_cloud,
		const Agenda &	ppath_step_agenda,
		const Numeric &	ppath_lmax,
		const Numeric &	ppath_lraytrace,
		const Numeric &	taustep_limit,
		const Agenda &	propmat_clearsky_agenda,
		const Index	stokes_dim,
		const Index	f_index,
		const Vector &	f_grid,
		const Vector &	p_grid,
		const Vector &	lat_grid,
		const Vector &	lon_grid,
		const Tensor3 &	z_field,
		const Vector &	refellipsoid,
		const Matrix &	z_surface,
		const Tensor3 &	t_field,
		const Tensor4 &	vmr_field,
		const ArrayOfIndex &	cloudbox_limits,
		const Tensor4 &	pnd_field,
		const ArrayOfArrayOfSingleScatteringData &	scat_data,
		const Verbosity &	verbosity
	)

mcPathTraceGeneral.

Performs the tasks of pathlength sampling.

Ray tracing done (but now only as far as determined by pathlength sampling) and calculation of the evolution operator and several atmospheric variables at the new point.

The end point of the ray tracing is returned by ppath_step, where the point of concern has index ppath_step.np-1. However, a somehwat dirty trick is used here to avoid copying of data. Only ppath.np is adjusted, and ppath_step can contain additional points (that should not be used).

Parameters

[in,out]	ws	Current workspace.
[out]	evol_op	Evolution operator (Stokes attenuation operator; exp(-tau)).
[out]	abs_vec_mono	Total monochromatic absorption vector.
[out]	temperature	A vector of temperatures.
[out]	ext_mat_mono	Total monochromatic extinction matrix.
[out]	rng	Random number generator instance.
[out]	rte_pos	Position for starting radiative transfer simulations.
[out]	rte_los	Incident line of sight for subsequent ray-tracing.
[out]	g	randomly chosen extinction path.
[out]	ppath_step	A propagation path step.
[out]	termination_flag	Flag defining whether the path of the photon is terminated
[in]	inside_cloud	Flag defining inside or not the cloud box
[in]	ppath_step_agenda	Calculation of a propagation path step.
[in]	ppath_lmax	Maximum length between points describing propagation paths.
[in]	ppath_lraytrace	Maximum length of ray tracing steps when determining propagation paths.
[in]	taustep_limit	Defines an upper step length in terms of optical thickness for Monte Carlo calculations.
[in]	propmat_clearsky_agenda	Agenda calculating the absorption coefficient matrices.
[in]	stokes_dim	The dimensionality of the Stokes vector (1-4).
[in]	f_index	Index of frequency grid point handeled.
[in]	f_grid	Frequency grid for monochromatic pencil beam calculations.
[in]	p_grid	Pressure grid.
[in]	lat_grid	Latitude grid.
[in]	lon_grid	Longitude grid.
[in]	z_field	The field of geometrical altitudes.
[in]	refellipsoid	Reference ellipsoid.
[in]	z_surface	The surface altitude.
[in]	t_field	The temperature grid.
[in]	vmr_field	VMR field.
[in]	cloudbox_limits	The limits of the cloud box.
[in]	pnd_field	Particle number density field.
[in]	scat_data	Array of single scattering data.
[in]	verbosity	Verbosity variable to dynamically control the reporting level during runtime.

Author

Cory Davis

Date

2005-2-21

Definition at line 711 of file montecarlo.cc.

References ARTS::Var::ext_mat(), and ARTS::Var::stokes_dim().

Referenced by MCGeneral().

mcPathTraceRadar()

void mcPathTraceRadar	(	Workspace &	ws,
		MatrixView	evol_op,
		Vector &	abs_vec_mono,
		Numeric &	temperature,
		MatrixView	ext_mat_mono,
		Rng &	rng,
		Vector &	rte_pos,
		Vector &	rte_los,
		Vector &	pnd_vec,
		Numeric &	stot,
		Numeric &	ttot,
		Ppath &	ppath_step,
		Index &	termination_flag,
		bool &	inside_cloud,
		const Agenda &	ppath_step_agenda,
		const Numeric &	ppath_lmax,
		const Numeric &	ppath_lraytrace,
		const Agenda &	propmat_clearsky_agenda,
		const bool &	anyptype_nonTotRan,
		const Index	stokes_dim,
		const Index	f_index,
		const Vector &	f_grid,
		const Vector &	Iprop,
		const Vector &	p_grid,
		const Vector &	lat_grid,
		const Vector &	lon_grid,
		const Tensor3 &	z_field,
		const Vector &	refellipsoid,
		const Matrix &	z_surface,
		const Tensor3 &	t_field,
		const Tensor4 &	vmr_field,
		const ArrayOfIndex &	cloudbox_limits,
		const Tensor4 &	pnd_field,
		const ArrayOfArrayOfSingleScatteringData &	scat_data_mono,
		const Verbosity &	verbosity
	)

mcPathTraceRadar.

Performs the tasks of pathlength sampling.

Ray tracing done (but now only as far as determined by pathlength sampling) and calculation of the evolution operator and several atmospheric variables at the new point.

The end point of the ray tracing is returned by ppath_step, where the point of concern has index ppath_step.np-1. However, a somehwat dirty trick is used here to avoid copying of data. Only ppath.np is adjusted, and ppath_step can contain additional points (that should not be used).

Parameters

[in,out]	ws	Current workspace.
[out]	evol_op	Evolution operator (Stokes attenuation operator; exp(-tau)).
[out]	abs_vec_mono	Total monochromatic absorption vector.
[out]	temperature	A vector of temperatures.
[out]	ext_mat_mono	Total monochromatic extinction matrix.
[out]	rng	Random number generator instance.
[out]	rte_pos	Position for starting radiative transfer simulations.
[out]	rte_los	Incident line of sight for subsequent ray-tracing.
[out]	stot	Starting point of total path lenght
[out]	ttot	Total path length *** FIXMEDOC ***
[out]	ppath_step	A propagation path step.
[out]	termination_flag	Flag defining whether the path of the photon is terminated
[in]	inside_cloud	Flag defining inside or not the cloud box
[in]	ppath_step_agenda	Calculation of a propagation path step.
[in]	ppath_lmax	Maximum length between points describing propagation paths.
[in]	ppath_lraytrace	Maximum length of ray tracing steps when determining propagation paths.
[in]	taustep_limit	Defines an upper step length in terms of optical thickness for Monte Carlo calculations.
[in]	propmat_clearsky_agenda	Agenda calculating the absorption coefficient matrices.
[in]	anyptype_nonTotRan	Flag definining any particle type, but for totally random oriented.
[in]	stokes_dim	The dimensionality of the Stokes vector (1-4).
[in]	f_index	Index of frequency grid point handeled.
[in]	f_grid	Frequency grid for monochromatic pencil beam calculations.
[in]	Iprop	Incident I component of the Stokes vector *** FIXMEDOC ***
[in]	p_grid	Pressure grid.
[in]	lat_grid	Latitude grid.
[in]	lon_grid	Longitude grid.
[in]	z_field	The field of geometrical altitudes.
[in]	refellipsoid	Reference ellipsoid.
[in]	z_surface	The surface altitude.
[in]	t_field	The temperature grid.
[in]	vmr_field	VMR field.
[in]	cloudbox_limits	The limits of the cloud box.
[in]	pnd_field	Particle number density field.
[in]	scat_data	Array of single scattering data.
[in]	verbosity	Verbosity variable to dynamically control the reporting level during runtime.

Author

Cory Davis (mcPathTraceGeneral), Ian S. Adams

Date

2015-09-08

Definition at line 1054 of file montecarlo.cc.

References clear_rt_vars_at_gp(), ARTS::Var::cloudbox_limits(), cloudy_rt_vars_at_gp(), CREATE_OUT0, Rng::draw(), ext2trans(), ARTS::Var::ext_mat(), ARTS::Var::f_grid(), ARTS::Var::f_index(), fractional_gp(), id_mat(), is_gp_inside_cloudbox(), joker, ARTS::Var::lat_grid(), ARTS::Var::lon_grid(), mult(), ARTS::Var::p_grid(), ARTS::Var::pnd_field(), ARTS::Var::ppath_lmax(), ARTS::Var::ppath_lraytrace(), ppath_start_stepping(), ARTS::Var::ppath_step(), ARTS::Var::ppath_step_agenda(), ppath_step_agendaExecute(), ppath_what_background(), ARTS::Var::propmat_clearsky_agenda(), ARTS::Var::refellipsoid(), ARTS::Var::rte_los(), ARTS::Var::rte_pos(), ARTS::Var::scat_data(), SPEED_OF_LIGHT, ARTS::Var::stokes_dim(), ARTS::Var::t_field(), ARTS::Var::verbosity(), ARTS::Var::vmr_field(), ARTS::Var::z_field(), and ARTS::Var::z_surface().

Referenced by MCRadar().

Sample_los()

void Sample_los	(	VectorView	new_rte_los,
		Numeric &	g_los_csc_theta,
		MatrixView	Z,
		Rng &	rng,
		ConstVectorView	rte_los,
		const ArrayOfArrayOfSingleScatteringData &	scat_data,
		const Index	stokes_dim,
		const Index	f_index,
		ConstVectorView	pnd_vec,
		ConstVectorView	Z11maxvector,
		const Numeric	Csca,
		const Numeric	rtp_temperature,
		const Index	t_interp_order = 1
	)

Sample_los.

Sampling the new incident direction according to a rejection method. Calculation of the bulk scattering phase matrix.

Parameters

[out]	new_rte_los	Incident line of sight for subsequent.
[out]	g_los_csc_theta	Probability density for the chosen direction multiplied by sin(za)
[out]	Z	Bulk phase matrix in Stokes notation.
[in,out]	rng	Rng random number generator instance.
[in]	rte_los	Incident line of sight for subsequent ray-tracing.
[in]	scat_data	As the WSV.
[in]	stokes_dim	As the WSV.
[out]	pnd_vec	Vector of particle number densities (one element per scattering element).
[in]	Z11maxvector	Vector holding the maximum phase function for each scattering element.
[in]	Csca	Scattering cross section
[in]	rtp_temperature	As the WSV.

Author

Cory Davis

Date

2003-06-19

Definition at line 1391 of file montecarlo.cc.

References Rng::draw(), ARTS::Var::f_index(), joker, mirror_los(), ConstVectorView::nelem(), pha_mat_Bulk(), pha_mat_NScatElems(), pha_mat_ScatSpecBulk(), RAD2DEG, ARTS::Var::rte_los(), ARTS::Var::rtp_temperature(), ARTS::Var::scat_data(), ARTS::Var::stokes_dim(), and TotalNumberOfElements().

Referenced by MCGeneral().

Sample_los_uniform()

void Sample_los_uniform	(	VectorView	new_rte_los,
		Rng &	rng
	)

Sample_los_uniform.

Sampling the new direction uniformly

Parameters

[out]	new_rte_los	Incident line of sight for subsequent.
[out]	rng	Rng random number generator instance.

Author

*** FIXMEDOC ***

Date

*** FIXMEDOC ***

Definition at line 1471 of file montecarlo.cc.

References Rng::draw(), and RAD2DEG.

Variable Documentation

SPEED_OF_LIGHT

const Numeric SPEED_OF_LIGHT

extern

Referenced by mcPathTraceRadar().