PG_Kernel< T > Class Template Reference

Represents a class for the proposed rough surface kernel applied to Poly-Gaussian surfaces. More...

#include <PG_Kernel.h>

Public Member Functions
	PG_Kernel ()
	Default constructor for PG_Kernel.
	PG_Kernel (Surface< T > surface, Gas< T > gas, void(*local_kernel)(T *, T *, T *, T *, T *), Matrix< T > incident_velocity, unsigned long num_particles, std::string sim_name)
	Constructor for PG_Kernel.
	~PG_Kernel ()
	Destructor for PG_Kernel.
Gas< T > &	get_gas ()
	Get the Gas object.
Surface< T > &	get_surface ()
	Get the Surface object.
T	random_sampler_1D (T(PG_Kernel::*pdf)(T, std::vector< T >), std::vector< T > parameters, T x0, T size, T domain_x[])
	Perform random sampling in 1D using the Metropolis-Hastings algorithm.
std::tuple< T, T >	random_sampler_2D (T(PG_Kernel::*pdf)(T, T, std::vector< T >), std::vector< T > parameters, T x0, T y0, T size_x, T size_y, T domain_x[], T domain_y[])
	Perform random sampling in 2D using the Metropolis-Hastings algorithm.
std::tuple< T, T >	random_sampler_angles (T(PG_Kernel::*pdf)(T, T, std::vector< T >), std::vector< T > parameters, T x0, T y0, T size_x, T size_y, T domain_x[], T domain_y[])
	Perform random sampling of angles in 2D using the Metropolis-Hastings algorithm.
T	mixture_pdf (T gamma, T gamma_dot, std::vector< T > parameters)
	Calculate the PDF of the control process gamma and its derivative gamma_dot, for Poly-Gaussian surfaces.
T	kirchhoff_pdf (T theta_r1, T theta_r2, std::vector< T > parameters)
	Calculate the reflected particle angular PDF according to the Kirchhoff model.
T	shadow (T theta_r1, T height, int direction)
	Calculate the probability of a reflected particle to escape the surface.
T	occlusion (T theta_r1, T height, T distance, int direction)
	Calculate the probability of a reflected particle to escape the surface, given a certain travelled horizontal distance.
T	height_0_pdf (T height_0, std::vector< T > parameters)
	Calculate the PDF for the height_0 parameter.
T	distance_pdf (T distance, std::vector< T > parameters)
	Calculate the PDF for the distance parameter.
Matrix< T >	global_to_local (Matrix< T > global_vector, T theta_i, T theta_r1, T theta_r2)
	Convert global coordinates to local coordinates.
Matrix< T >	local_to_global (Matrix< T > local_vector, T theta_i, T theta_r1, T theta_r2)
	Convert local coordinates to global coordinates.
Matrix< T >	angles_to_slopes (T theta_i, T theta_r1, T theta_r2)
	Convert angles to slopes.
trajectory< T >	sample_particle ()
	Sample a single particle trajectory.
std::vector< trajectory< T > >	sample_batch ()
	Sample a batch of particle trajectories.
void	save (std::vector< trajectory< T > > trajectories, std::string filename)
	Save the trajectories to a file.
void	combine_files (std::string filename, int num_procs)
	Combine multiple trajectory files into one.
void	set_num_particles (unsigned long num_particles)
	Set the number of particles.
std::vector< trajectory< T > >	import_data (std::string filename)
	Import trajectory data from a file.
std::string &	get_sim_name ()
	Get the simulation name.
unsigned long	get_num_particles ()
	Get the number of particles.

Detailed Description

template<typename T>
class PG_Kernel< T >

Represents a class for the proposed rough surface kernel applied to Poly-Gaussian surfaces.

This class implements the rough GSI kernel algorithm for trajectory sampling. It returns the trajectories of free-molecular-flow gas particles on a rough surface.

Template Parameters

T	The type of the elements in the PG_Kernel.

Constructor & Destructor Documentation

PG_Kernel() [1/2]

template<typename T >

PG_Kernel< T >::PG_Kernel ( )

inline

Default constructor for PG_Kernel.

Initializes the PG_Kernel object with default values.

PG_Kernel() [2/2]

template<typename T >

PG_Kernel< T >::PG_Kernel ( Surface< T > surface, Gas< T > gas, void(* local_kernel )(T *, T *, T *, T *, T *), Matrix< T > incident_velocity, unsigned long num_particles, std::string sim_name )

inline

Constructor for PG_Kernel.

Initializes the PG_Kernel object with the given parameters.

Parameters

surface	The Surface object representing the surface properties.
gas	The Gas object representing the gas properties.
local_kernel	Pointer to the local kernel function.
incident_velocity	Matrix of incident velocities.
num_particles	Number of particles.
sim_name	Name of the simulation.

~PG_Kernel()

template<typename T >

PG_Kernel< T >::~PG_Kernel ( )

inline

Destructor for PG_Kernel.

Cleans up the PG_Kernel object.

Member Function Documentation

angles_to_slopes()

template<typename T >

Matrix< T > PG_Kernel< T >::angles_to_slopes	(	T	theta_i,
		T	theta_r1,
		T	theta_r2 )

Convert angles to slopes.

Parameters

theta_i	The theta_i value.
theta_r1	The theta_r1 value.
theta_r2	The theta_r2 value.

Returns

Matrix<T> The slopes.

combine_files()

template<typename T >

void PG_Kernel< T >::combine_files	(	std::string	filename,
		int	num_procs )

Combine multiple trajectory files into one.

Parameters

filename	The name of the file.
num_procs	The number of processes.

distance_pdf()

template<typename T >

T PG_Kernel< T >::distance_pdf	(	T	distance,
		std::vector< T >	parameters )

Calculate the PDF for the distance parameter.

Parameters

distance	The distance value.
parameters	Vector of parameters for the PDF function.

Returns

T The PDF value.

get_gas()

template<typename T >

Gas< T > & PG_Kernel< T >::get_gas ( )

inline

Get the Gas object.

Returns

Gas<T>& The Gas object.

get_num_particles()

template<typename T >

unsigned long PG_Kernel< T >::get_num_particles ( )

inline

Get the number of particles.

Returns

unsigned long The number of particles.

get_sim_name()

template<typename T >

std::string & PG_Kernel< T >::get_sim_name ( )

inline

Get the simulation name.

Returns

std::string& The simulation name.

get_surface()

template<typename T >

Surface< T > & PG_Kernel< T >::get_surface ( )

inline

Get the Surface object.

Returns

Surface<T>& The Surface object.

global_to_local()

template<typename T >

Matrix< T > PG_Kernel< T >::global_to_local	(	Matrix< T >	global_vector,
		T	theta_i,
		T	theta_r1,
		T	theta_r2 )

Convert global coordinates to local coordinates.

Parameters

global_vector	The global vector.
theta_i	The theta_i value.
theta_r1	The theta_r1 value.
theta_r2	The theta_r2 value.

Returns

Matrix<T> The local vector.

height_0_pdf()

template<typename T >

T PG_Kernel< T >::height_0_pdf	(	T	height_0,
		std::vector< T >	parameters )

Calculate the PDF for the height_0 parameter.

Parameters

height_0	The height_0 value.
parameters	Vector of parameters for the PDF function.

Returns

T The PDF value.

import_data()

template<typename T >

std::vector< trajectory< T > > PG_Kernel< T >::import_data

(

std::string

filename

)

Import trajectory data from a file.

Parameters

filename

The name of the file.

Returns

std::vector<trajectory<T>> The imported trajectories.

kirchhoff_pdf()

template<typename T >

T PG_Kernel< T >::kirchhoff_pdf	(	T	theta_r1,
		T	theta_r2,
		std::vector< T >	parameters )

Calculate the reflected particle angular PDF according to the Kirchhoff model.

Parameters

theta_r1	The theta_r1 angle value.
theta_r2	The theta_r2 angle value.
parameters	Auxiliary parameters required: incidence angle and control process values.

Returns

T The PDF value.

local_to_global()

template<typename T >

Matrix< T > PG_Kernel< T >::local_to_global	(	Matrix< T >	local_vector,
		T	theta_i,
		T	theta_r1,
		T	theta_r2 )

Convert local coordinates to global coordinates.

Parameters

local_vector	The local vector.
theta_i	The theta_i value.
theta_r1	The theta_r1 value.
theta_r2	The theta_r2 value.

Returns

Matrix<T> The global vector.

mixture_pdf()

template<typename T >

T PG_Kernel< T >::mixture_pdf	(	T	gamma,
		T	gamma_dot,
		std::vector< T >	parameters )

Calculate the PDF of the control process gamma and its derivative gamma_dot, for Poly-Gaussian surfaces.

Parameters

gamma	The gamma value.
gamma_dot	The gamma_dot value.
parameters	Vector of parameters for the PDF function.

Returns

T The PDF value.

occlusion()

template<typename T >

T PG_Kernel< T >::occlusion	(	T	theta_r1,
		T	height,
		T	distance,
		int	direction )

Calculate the probability of a reflected particle to escape the surface, given a certain travelled horizontal distance.

Parameters

theta_r1	The theta_r1 angle.
height	The non-dimensional height of the particle.
distance	The horizontal distance value.
direction	The direction of the particle trajectory.

Returns

T The value of the probability.

random_sampler_1D()

template<typename T >

T PG_Kernel< T >::random_sampler_1D	(	T(PG_Kernel< T >::*	pdf )(T, std::vector< T >),
		std::vector< T >	parameters,
		T	x0,
		T	size,
		T	domain_x[] )

Perform random sampling in 1D using the Metropolis-Hastings algorithm.

Parameters

pdf	Pointer to the PDF function.
parameters	Vector of parameters for the PDF function.
x0	Initial position.
size	Size of the sampling range.
domain_x	Array of domain limits.

Returns

T The sampled value.

random_sampler_2D()

template<typename T >

std::tuple< T, T > PG_Kernel< T >::random_sampler_2D	(	T(PG_Kernel< T >::*	pdf )(T, T, std::vector< T >),
		std::vector< T >	parameters,
		T	x0,
		T	y0,
		T	size_x,
		T	size_y,
		T	domain_x[],
		T	domain_y[] )

Perform random sampling in 2D using the Metropolis-Hastings algorithm.

Parameters

pdf	Pointer to the PDF function.
parameters	Vector of parameters for the PDF function.
x0	Initial x position.
y0	Initial y position.
size_x	Size of the x sampling range.
size_y	Size of the y sampling range.
domain_x	Array of x domain limits.
domain_y	Array of y domain limits.

Returns

std::tuple<T, T> The sampled x and y values.

random_sampler_angles()

template<typename T >

std::tuple< T, T > PG_Kernel< T >::random_sampler_angles	(	T(PG_Kernel< T >::*	pdf )(T, T, std::vector< T >),
		std::vector< T >	parameters,
		T	x0,
		T	y0,
		T	size_x,
		T	size_y,
		T	domain_x[],
		T	domain_y[] )

Perform random sampling of angles in 2D using the Metropolis-Hastings algorithm.

Parameters

pdf	Pointer to the PDF function.
parameters	Vector of parameters for the PDF function.
x0	Initial x position.
y0	Initial y position.
size_x	Size of the x sampling range.
size_y	Size of the y sampling range.
domain_x	Array of x domain limits.
domain_y	Array of y domain limits.

Returns

std::tuple<T, T> The sampled theta_r1 and theta_r2 values.

sample_batch()

template<typename T >

std::vector< trajectory< T > > PG_Kernel< T >::sample_batch

(

)

Sample a batch of particle trajectories.

Returns

std::vector<trajectory<T>> The sampled trajectories.

sample_particle()

template<typename T >

trajectory< T > PG_Kernel< T >::sample_particle

(

)

Sample a single particle trajectory.

Returns

trajectory<T> The sampled trajectory.

save()

template<typename T >

void PG_Kernel< T >::save	(	std::vector< trajectory< T > >	trajectories,
		std::string	filename )

Save the trajectories to a file.

Parameters

trajectories	The trajectories to save.
filename	The name of the file.

set_num_particles()

template<typename T >

void PG_Kernel< T >::set_num_particles ( unsigned long num_particles )

inline

Set the number of particles.

Parameters

num_particles

The number of particles.

shadow()

template<typename T >

T PG_Kernel< T >::shadow	(	T	theta_r1,
		T	height,
		int	direction )

Calculate the probability of a reflected particle to escape the surface.

Parameters

theta_r1	The theta_r1 angle.
height	The non-dimensional height of the particle.
direction	The direction of the particle trajectory.

Returns

T The value of the probability.

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The documentation for this class was generated from the following file:

• src/PG_Kernel.h