An envelope geometry class. More...

#include <egs_envelope_geometry.h>

Inheritance diagram for EGS_EnvelopeGeometry:

Public Member Functions
	EGS_EnvelopeGeometry (EGS_BaseGeometry G, const vector< EGS_BaseGeometry > &geoms, const string &Name="", bool newindexing=false)

bool	isRealRegion (int ireg) const

bool	isInside (const EGS_Vector &x)

int	isWhere (const EGS_Vector &x)

int	inside (const EGS_Vector &x)

int	medium (int ireg) const

int	computeIntersections (int ireg, int n, const EGS_Vector &X, const EGS_Vector &u, EGS_GeometryIntersections *isections)

EGS_Float	howfarToOutside (int ireg, const EGS_Vector &x, const EGS_Vector &u)

int	howfar (int ireg, const EGS_Vector &x, const EGS_Vector &u, EGS_Float &t, int newmed=0, EGS_Vector normal=0)

EGS_Float	hownear (int ireg, const EGS_Vector &x)

int	getMaxStep () const

bool	hasBooleanProperty (int ireg, EGS_BPType prop) const

void	setBooleanProperty (EGS_BPType)

void	addBooleanProperty (int)

void	setBooleanProperty (EGS_BPType, int, int, int step=1)

void	addBooleanProperty (int, int, int, int step=1)

const string &	getType () const

EGS_BaseGeometry **	getInscribedGeometries (std::size_t &nInscribed) const

void	printInfo () const

void	setRelativeRho (int start, int end, EGS_Float rho)

void	setRelativeRho (EGS_Input *)

EGS_Float	getRelativeRho (int ireg) const

void	setBScaling (int start, int end, EGS_Float bf)

void	setBScaling (EGS_Input *)

EGS_Float	getBScaling (int ireg) const

virtual void	getLabelRegions (const string &str, vector< int > &regs)

Public Member Functions inherited from EGS_BaseGeometry
	EGS_BaseGeometry (const string &Name)
	Construct a geometry named Name. More...

virtual	~EGS_BaseGeometry ()
	Destructor. More...

bool	isConvex () const
	Is the geometry convex? More...

virtual EGS_Float	getVolume (int ireg)
	Calculates the volume of region ireg. More...

virtual EGS_Float	getBound (int idir, int ind)
	Returns region boundaries in direction determined by idir. More...

virtual int	getNRegDir (int idir)

int	regions () const
	Returns the number of local regions in this geometry. More...

void	setMedium (const string &Name)
	Set all regions to a medium with name Name. More...

void	setMedium (int start, int end, const string &Name, int delta=1)
	Set every delta'th region between start and end to the medium named Name. More...

void	setMedium (int imed)
	Set all regions to a medium with index imed. More...

void	setMedium (int istart, int iend, int imed, int delta=1)
	Set every delta'th region between start and end (inclusive) to imed. More...

void	setMedia (EGS_Input *inp)
	Set the media in the geometry from the input pointed to by inp. More...

bool	hasRhoScaling () const
	Does this geometry object have a mass density scaling feature? More...

EGS_Float	getMediumRho (int ind) const

virtual void	setApplication (EGS_Application *app)

bool	hasBScaling () const
	Does this geometry object have a B field scaling feature?

const string &	getName () const
	Get the name of this geometry. More...

void	setDebug (bool deb)
	Turn debugging on. More...

void	setName (EGS_Input *inp)
	Set the name of the geometry from the input inp. More...

void	setBoundaryTolerance (EGS_Input *inp)
	Set the value of the boundary tolerance from the input inp. More...

void	setBoundaryTolerance (EGS_Float tol)
	Set the value of the boundary tolerance from argument.

int	ref ()
	Increase the reference count to this geometry. More...

int	deref ()
	Decrease the reference count to this geometry. More...

EGS_Float	getBoundaryTolerance ()
	Get the value of the boundary tolerance.

virtual void	getNumberRegions (const string &str, vector< int > &regs)
	Get a list of all the regions labeled with a number.

virtual const string &	getLabelName (const int i)
	Get the name of the i-th explicit label in the geometry.

virtual int	getLabelCount ()
	Get the number of explicit labels in the geometry.

int	setLabels (EGS_Input *input)
	Set the labels from an input block.

int	setLabels (const string &inp)
	Set the labels from an input string.

Protected Member Functions
void	setMedia (EGS_Input , int, const int )
	Don't set media for an envelope geometry. More...

Protected Attributes
EGS_BaseGeometry *	g
	The envelope geometry.

EGS_BaseGeometry **	geometries
	The inscribed geometries.

int	n_in
	Number of inscribed geometries.

int	nbase
	Number of regions in the base geometry.

int	nmax

bool	new_indexing
	If true, use new indexing style.

int *	reg_to_inscr
	Region to inscribed geometry conversion.

int *	local_start
	First region for each inscribed geometry.

Protected Attributes inherited from EGS_BaseGeometry
int	nreg
	Number of local regions in this geometry. More...

string	name
	Name of this geometry. More...

short *	region_media
	Array of media indeces. More...

int	med
	Medium index. More...

bool	has_rho_scaling
	Does this geometry have relative mass density scvaling? More...

EGS_Float *	rhor
	Array with relative mass densities. More...

bool	has_B_scaling
	Does this geometry has B field scaling factor? More...

bool	has_Ref_rho

EGS_Float *	bfactor
	Array with B field scaling factors. More...

EGS_Float	rhoRef
	Reference density for B field scaling. More...

int	nref
	Number of references to this geometry. More...

bool	debug
	Debugging flag. More...

bool	is_convex
	Is this geometry convex? More...

EGS_BPType	bproperty
	A bit mask of boolean properties for the entire geometry. More...

EGS_BPType *	bp_array
	An array of boolean properties on a region by region basis. More...

EGS_Float	boundaryTolerance
	Boundary tolerance for geometries that need it.

EGS_Float	halfBoundaryTolerance

vector< label >	labels
	Labels. More...

EGS_Application *	app
	The application this object belongs to.

Static Protected Attributes
static string	type = "EGS_EnvelopeGeometry"
	Geometry type.

Static Protected Attributes inherited from EGS_BaseGeometry
static int	error_flag = 0
	Set to non-zero status if a geometry problem is encountered.

Additional Inherited Members
Static Public Member Functions inherited from EGS_BaseGeometry
static int	findRegion (EGS_Float xp, int np, const EGS_Float *p)
	Find the bin to which xp belongs, given np bin edges p. More...

static int	nMedia ()
	Get the number of media registered so far by all geometries. More...

static const char *	getMediumName (int ind)
	Get the name of medium with index ind. More...

static int	addMedium (const string &medname)
	Add a medium or get the index of an existing medium. More...

static int	getMediumIndex (const string &medname)
	Get the index of a medium named medname. More...

static EGS_BaseGeometry *	createGeometry (EGS_Input *)
	Create a geometry (or geometries) from a given input. More...

static EGS_BaseGeometry *	createSingleGeometry (EGS_Input *inp)
	Create a single geometry from the input inp. More...

static void	clearGeometries ()
	Clears (deletes) all geometries in the currently active geometry list. More...

static EGS_BaseGeometry *	getGeometry (const string &Name)
	Get a pointer to the geometry named Name. More...

static EGS_BaseGeometry **	getGeometries ()

static int	getNGeometries ()

static string	getUniqueName ()
	Get a unique geometry name. More...

static void	describeGeometries ()
	Describes all existing geometries. More...

static void	setActiveGeometryList (int list)
	Set the currently active geometry list. More...

static int	getLastError ()

static void	resetErrorFlag ()

Detailed Description

An envelope geometry class.

An envelope geometry is a geometry consisting of a base geometry $G_B$ (the envelope) and one or more inscribed geometries $G_i, i=1,...,N$ . As a very simple example consider a box (the envelope) and e.g. a sphere (the inscribed geometry) inside the box. There can be much more complex geometries modeled as envelope geometries and more examples will be given after the details of the implementation of the various geometry methods:

A position is considered to be inside an envelope geometry if it inside the envelope .
If the envelope consists of regions and the inscribed geometries have regions with denoting the maximum of , then the region index of a point inside the envelope geometry is determined as follows:
- If the point is outside of all inscribed geometries, the region index is given by the region index in the envelope.
- If the point is inside of the 'th inscribed geometry and the local index in this geometry is , then the region index is given by $n_B + n_{\rm max} (j-1) + i_j$ . Note that this implies that the envelope has $n_B + n_{\rm max} N$ regions instead of $n_B + n_1 + \cdots n_N$ as one would expect. This approach is used because during the simulation only a single global region index is kept and in order to determine if the position is in the envelope geometry or one of the inscribed geometries it is much faster to use such a region indexing scheme (if index is less than , then the particle is in the envelope, otherwise subtract and divide by $n_{\rm max}$ to determine the index of the inscribed geometry). Such an indexing scheme is not a problem in practice as particles will never enter non-existing regions.
If the position is outside, the howfar() method is simple: just use the howfar() method of the envelope. If the position is inside, then
- If the position is in one of the inscribed geometries, use the howfar() method of this geometry only. If the particle will remain in the inscribed geometry, the new region index is determined from the index of the inscribed geometry in the list of inscribed geometries and the new region index. If the particles exits the inscribed geometry, the new region index becomes the region index in the envelope.
- If the particle is not in any of the inscribed geometries, then the distance to a boundary is given by the minimum of the distances to a boundary of the envelope or any of the inscribed geometries. The new region index is either the new region in the envelope or determined by the entry region index of the inscribed geometry being entered, depending on which distance is smallest.
The hownear() is simple if the position is outside: just use the hownear() method of the envelope. If the position is inside, then
- If the position is inside one of the inscribed geometries, $t_\perp$ is given by the hownear() method of this geometry
- If the position is outside of all inscribed geometries, $t_\perp$ is given by the minimum of the minimum perpendicular distances to the envelope and all inscribed geometries.

The above explanation makes it clear that any type of a geometry can be used as the envelope or an inscribed geometry as long as the logic applies. The conditions for the applicability of the above logic are:

Inscribed geometries can not overlap. Undefined behavior will result if they do overlap (e.g. depending on whether the particle entered two overlapping geometries from the first or second geometry, the regions and media of that geometry will determine the transport as long as the particle remains in the geometry)
The envelope must completely enclose the inscribed geometries. If this is not the case and a particle enters an inscribed geometry that extends outside of the envelope, the particle will be considered inside even if it is outside the envelope for as long as the particle remains in the inscribed geometry.

Apart for these two restrictions any geometries can be used. In particular, neither the envelope nor the inscribed geometries need to be elementary geometries. More complex examples of the use of this type of a composite geometry are:

An XYZ-geometry inscribed in a box of air useful for e.g. external beam radiotherapy calculations
A complex geometry such as a brachytherapy seed inscribed in an XYZ geometry. One would use this type of geometry if one wanted to calculate the complete 3D dose distribution in a given voxel grid for one or more radioactive sources.
A complex geometry representing a detailed model of an ionization chamber inscribed in a box of water. This is very useful for dosimetry standards simulations.
Sets of non-concentric cylinders or spheres.

One should keep in mind that an envelope geometry becomes slower with increasing number of inscribed objects. In situations with many such objects it may be advantageous to combine several objects into some other composite geometry (e.g. a geometry union, a stack, another envelope, etc.) before inscribing into the envelope.

An envelope geometry can be defined using the following keys:

library = egs_genvelope
base geometry = name of a previously defined geometry
inscribed geometries = list of names of previously defined geometries

The above should be self explanatory. Example geometry files making use of an envelope geometry are car.geom, chambers_in_box.geom, rz1.geom, seeds_in_xyz.geom and seeds_in_xyz1.geom.

A simple example:

:start geometry definition:
    :start geometry:
        name        = my_box
        library     = egs_box
        box size    = 1 2 3
        :start media input:
            media = water
        :stop media input:
    :stop geometry:

    :start geometry:
        name        = g1
        library     = egs_spheres
        midpoint = 0 0 1
        radii = 0.3
        :start media input:
            media = air
        :stop media input:
    :stop geometry:

    :start geometry:
        name        = g2
        library     = egs_spheres
        midpoint = 0 0 -1
        radii = 0.3
        :start media input:
            media = air
        :stop media input:
    :stop geometry:

    :start geometry:
        name        = my_envelope
        library     = egs_genvelope
        base geometry = my_box

        # Inscribed geometries must be strictly inside the envelope
        # No touching of surfaces!
        inscribed geometries = g1 g2
    :stop geometry:

    simulation geometry = my_envelope

:stop geometry definition:

A simple example

Definition at line 229 of file egs_envelope_geometry.h.

Member Function Documentation

void EGS_EnvelopeGeometry::setMedia	(	EGS_Input *	,
		int	,
		const int *
	)

protectedvirtual

Don't set media for an envelope geometry.

This function is re-implemented to warn the user to not set media in the envelope geometry. Instead, media should be set for the envelope and in the inscribed geometries.

Reimplemented from EGS_BaseGeometry.

Definition at line 49 of file egs_envelope_geometry.cpp.

References egsWarning.

Member Data Documentation

int EGS_EnvelopeGeometry::nmax

protected

Max. number of regions in any inscribed geometry

Definition at line 602 of file egs_envelope_geometry.h.

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

/home/rwtownson/EGSnrc/HEN_HOUSE/egs++/geometry/egs_genvelope/egs_envelope_geometry.h
/home/rwtownson/EGSnrc/HEN_HOUSE/egs++/geometry/egs_genvelope/egs_envelope_geometry.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Detailed Description

Member Function Documentation

Member Data Documentation