clipper::Grid_sampling Class Reference

Grid sampling of a unit cell. More...

#include <coords.h>

Inheritance diagram for clipper::Grid_sampling:

List of all members.

Public Member Functions
	Grid_sampling ()
	null constructor
	Grid_sampling (const int &nu, const int &nv, const int &nw)
	constructor: from nu, nv, nw
	Grid_sampling (const Spacegroup &spacegroup, const Cell &cell, const Resolution &resol, const ftype rate=1.5)
	constructor: from Spacegroup, Cell, Resolution, Shannon rate
void	init (const Spacegroup &spacegroup, const Cell &cell, const Resolution &resol, const ftype rate=1.5)
	initialiser: from Spacegroup, Cell, Resolution, Shannon rate
Mat33	matrix_grid_frac () const
	return matrix which converts grid to fractional coordinates
Mat33	matrix_frac_grid () const
	return matrix which converts fractional to grid coordinates
bool	is_null () const
	test if object has been initialised
const int &	nu () const
	get nu
const int &	nv () const
	get nv
const int &	nw () const
	get nw
int	size () const
	return size of grid array
int	index (const Coord_grid &c) const
	grid indexing operator
Coord_grid	deindex (const int &index) const
	grid deindexing operator
const String	format () const
	return formatted String representation

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Detailed Description

Grid sampling of a unit cell.

This class represents the grid sampling of a unit cell. It is otherwise identical to its parent, clipper::Grid_cell, but has an additional constructor which takes a spacegroup, cell and resolution and produces an appropriate grid obeying all of the symmetry constraints, and using efficient factors for the calculation of FFTs.

Note:

The following methods are inherited from Grid and Grid_cell but are documented here for convenience: nu(), nv(), nw(), size(), index(), deindex(), format(), coord_frac(), coord_grid(), to_unit().

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Constructor & Destructor Documentation

clipper::Grid_sampling::Grid_sampling	(	const Spacegroup &	spacegroup,
		const Cell &	cell,
		const Resolution &	resol,
		const ftype	rate = 1.5
	)

constructor: from Spacegroup, Cell, Resolution, Shannon rate

A grid is chosen to represent the specified cell at the given resolution, obeying any restrictions imposed by the spacegroup. A slightly finer grid may be chosen if doing so is liable to significantly increase the speed of FFTs on that grid.

Parameters:

spacegroup	The spacegroup which the grid must obey.
cell	The cell which the grid must contain.
resol	The resolution to which the grid must sample.
rate	The linear Shannon rate (oversampling) required. If rate = 1, the grid spaceing will be half the resolution (the the minimum required). For a grid spaceing of resol/3, use the default rate=1.5.

References init().

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Member Function Documentation

void clipper::Grid_sampling::init	(	const Spacegroup &	spacegroup,
		const Cell &	cell,
		const Resolution &	resol,
		const ftype	rate = 1.5
	)

initialiser: from Spacegroup, Cell, Resolution, Shannon rate

A grid is chosen to represent the specified cell at the given resolution, obeying any restrictions imposed by the spacegroup. A slightly finer grid may be chosen if doing so is liable to significantly increase the speed of FFTs on that grid.

Parameters:

spacegroup	The spacegroup which the grid must obey.
cell	The cell which the grid must contain.
resol	The resolution to which the grid must sample.
rate	The linear Shannon rate (oversampling) required. If rate = 1, the grid spaceing will be half the resolution (the the minimum required). For a grid spaceing of resol/3, use the default rate=1.5.

Reimplemented in clipper::CGrid_sampling.

References clipper::Cell_descr::a(), clipper::Cell_descr::b(), clipper::Cell_descr::c(), clipper::Cell::descr(), clipper::Util::intc(), clipper::Resolution::limit(), clipper::Util::max(), clipper::Util::mod(), clipper::Spacegroup::num_symops(), and clipper::Spacegroup::symop().

Referenced by Grid_sampling(), and clipper::CGrid_sampling::init().

Mat33 clipper::Grid_sampling::matrix_grid_frac

(

)

const

return matrix which converts grid to fractional coordinates

The result is an RT operator. This is a redudent representation, but is handy for assembling compound operators.

Returns:

The operator

References nu(), nv(), and nw().

Referenced by clipper::Xmap_base::init().

Mat33 clipper::Grid_sampling::matrix_frac_grid

(

)

const

return matrix which converts fractional to grid coordinates

The result is an RT operator. This is a redudent representation, but is handy for assembling compound operators.

Returns:

The operator

References nu(), nv(), and nw().

Referenced by clipper::NX_operator::init(), and clipper::NXmap_base::init().

bool clipper::Grid_sampling::is_null

(

)

const

test if object has been initialised

Returns:

true if the object has not been initalised.

Reimplemented from clipper::Vec3< int >.

References size().

Referenced by clipper::CNXmap_operator< T >::init(), clipper::CXmap< T >::init(), clipper::Xmap_base::is_null(), and clipper::CGrid_sampling::update().

const String clipper::Grid_sampling::format

(

)

const

return formatted String representation

Returns:

The formatted text string

Reimplemented from clipper::Grid.

Referenced by clipper::Xmap_cacheobj::format().

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

• coords.h
• coords.cpp