Clipper

Grid sampling of a unit cell. More...
#include <coords.h>
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 
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.
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.
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().
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.
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.
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.
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
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
Reimplemented from clipper::Grid.
Referenced by clipper::Xmap_cacheobj::format().