clipper::Grid_sampling Class Reference

Grid sampling of a unit cell. More...

#include <coords.h>

Inheritance diagram for clipper::Grid_sampling:

clipper::Grid clipper::Vec3< int > clipper::CGrid_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


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().

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.


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.

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

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

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 >.

const String clipper::Grid_sampling::format (  )  const

return formatted String representation

Returns:
The formatted text string

Reimplemented from clipper::Grid.


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

Generated on Fri Jun 12 18:03:40 2009 for Clipper by  doxygen 1.5.9