EMAN::Util::KaiserBessel Class Reference

1-D Kaiser-Bessel window function class. More...

#include <util.h>

Inheritance diagram for EMAN::Util::KaiserBessel:

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List of all members.

Public Member Functions

 KaiserBessel (float alpha_, int K, float r_, float v_, int N_, float vtable_=0.f, int ntable_=5999)
virtual ~KaiserBessel ()
float I0table_maxerror ()
 Compute the maximum error in the table.
vector< float > dump_table ()
virtual float sinhwin (float x) const
 Kaiser-Bessel Sinh window function.
virtual float i0win (float x) const
 Kaiser-Bessel I0 window function.
float i0win_tab (float x) const
 Kaiser-Bessel I0 window function (uses table lookup).
int get_window_size () const
 Return the size of the I0 window.
kbsinh_win get_kbsinh_win ()
 Sinh window function object factory.
kbi0_win get_kbi0_win ()
 I0 window function object factory.

Protected Member Functions

virtual void build_I0table ()
 2*pi*alpha*r*vadjust

Protected Attributes

float alpha
float v
float r
int N
 Kaiser-Bessel parameters.
int K
 size in Ix-space
float vtable
 I0 window size.
int ntable
 table I0 non-zero domain maximum
vector< float > i0table
float dtable
float alphar
 table spacing
float fac
 alpha*r
float vadjust
 2*pi*alpha*r*v
float facadj
float fltb
 Tabulate I0 window for speed.

Classes

class  kbi0_win
 I0 window function object. More...
class  kbsinh_win
 Sinh window function object. More...

Detailed Description

1-D Kaiser-Bessel window function class.

(It's a class so that the windowing parameters may be instantiated and held in the instance object.)

The I0 version can be tabulated and interpolated upon demand, but the max error needs to be checked. The "vtable" parameter corresponds to the maximum value of x for which the I0 window is non-zero. Setting "vtable" different from "v" corresponds to a change in units of x. In practice, it is often handy to replace x in some sort of absolute units with x described in terms of grid intervals.

The get_kbsinh_win and get_kbi0_win functions return single-argument function objects, which is what a generic routine is likely to want.

See also:
P. A. Penczek, R. Renka, and H. Schomberg, J. Opt. Soc. Am. _21_, 449 (2004)

Definition at line 271 of file util.h.

Constructor & Destructor Documentation

Util::KaiserBessel::KaiserBessel ( float  alpha_,
int  K,
float  r_,
float  v_,
int  N_,
float  vtable_ = 0.f,
int  ntable_ = 5999 
)

Definition at line 2008 of file util_sparx.cpp.

References alpha, alphar, build_I0table(), fac, facadj, K, r, twopi, v, vadjust, and vtable.

02010                 : alpha(alpha_), v(v_), r(r_), N(N_), K(K_), vtable(vtable_),
02011                   ntable(ntable_) {
02012         // Default values are alpha=1.25, K=6, r=0.5, v = K/2
02013         if (0.f == v) v = float(K)/2;
02014         if (0.f == vtable) vtable = v;
02015         alphar = alpha*r;
02016         fac = static_cast<float>(twopi)*alphar*v;
02017         vadjust = 1.0f*v;
02018         facadj = static_cast<float>(twopi)*alphar*vadjust;
02019         build_I0table();
02020 }

virtual EMAN::Util::KaiserBessel::~KaiserBessel (  )  [inline, virtual]

Definition at line 291 of file util.h.

00438 {

Member Function Documentation

void Util::KaiserBessel::build_I0table (  )  [protected, virtual]

2*pi*alpha*r*vadjust

Reimplemented in EMAN::Util::FakeKaiserBessel.

Definition at line 2031 of file util_sparx.cpp.

References facadj, fltb, i0table, K, N, ntable, EMAN::Util::round(), sqrt(), and vadjust.

Referenced by KaiserBessel().

02031                                      {
02032         i0table.resize(ntable+1); // i0table[0:ntable]
02033         int ltab = int(round(float(ntable)/1.25f));
02034         fltb = float(ltab)/(K/2);
02035         float val0 = static_cast<float>(gsl_sf_bessel_I0(facadj));
02036         for (int i=ltab+1; i <= ntable; i++) i0table[i] = 0.f;
02037         for (int i=0; i <= ltab; i++) {
02038                 float s = float(i)/fltb/N;
02039                 if (s < vadjust) {
02040                         float rt = sqrt(1.f - pow(s/vadjust, 2));
02041                         i0table[i] = static_cast<float>(gsl_sf_bessel_I0(facadj*rt))/val0;
02042                 } else {
02043                         i0table[i] = 0.f;
02044                 }
02045 //              cout << "  "<<s*N<<"  "<<i0table[i] <<endl;
02046         }
02047 }

float Util::KaiserBessel::I0table_maxerror (  ) 

Compute the maximum error in the table.

Definition at line 2049 of file util_sparx.cpp.

References i0table, and ntable.

02049                                          {
02050         float maxdiff = 0.f;
02051         for (int i = 1; i <= ntable; i++) {
02052                 float diff = fabs(i0table[i] - i0table[i-1]);
02053                 if (diff > maxdiff) maxdiff = diff;
02054         }
02055         return maxdiff;
02056 }

vector<float> EMAN::Util::KaiserBessel::dump_table (  )  [inline]

Definition at line 294 of file util.h.

00438                 {

float Util::KaiserBessel::sinhwin ( float  x  )  const [virtual]

Kaiser-Bessel Sinh window function.

Reimplemented in EMAN::Util::FakeKaiserBessel.

Definition at line 2058 of file util_sparx.cpp.

References alphar, fac, and sqrt().

Referenced by EMAN::EMData::divkbsinh(), and EMAN::Processor::EMFourierFilterFunc().

02058                                              {
02059         float val0 = sinh(fac)/fac;
02060         float absx = fabs(x);
02061         if (0.0 == x) {
02062                 float res = 1.0f;
02063                 return res;
02064         } else if (absx == alphar) {
02065                 return 1.0f/val0;
02066         } else if (absx < alphar) {
02067                 float rt = sqrt(1.0f - pow((x/alphar), 2));
02068                 float facrt = fac*rt;
02069                 float res = (sinh(facrt)/facrt)/val0;
02070                 return res;
02071         } else {
02072                 float rt = sqrt(pow((x/alphar),2) - 1.f);
02073                 float facrt = fac*rt;
02074                 float res = (sin(facrt)/facrt)/val0;
02075                 return res;
02076         }
02077 }

float Util::KaiserBessel::i0win ( float  x  )  const [virtual]

Kaiser-Bessel I0 window function.

Reimplemented in EMAN::Util::FakeKaiserBessel.

Definition at line 2022 of file util_sparx.cpp.

References facadj, sqrt(), and vadjust.

Referenced by EMAN::Processor::EMFourierFilterFunc().

02022                                            {
02023         float val0 = float(gsl_sf_bessel_I0(facadj));
02024         float absx = fabs(x);
02025         if (absx > vadjust) return 0.f;
02026         float rt = sqrt(1.f - pow(absx/vadjust, 2));
02027         float res = static_cast<float>(gsl_sf_bessel_I0(facadj*rt))/val0;
02028         return res;
02029 }

float EMAN::Util::KaiserBessel::i0win_tab ( float  x  )  const [inline]

Kaiser-Bessel I0 window function (uses table lookup).

Definition at line 302 of file util.h.

Referenced by EMAN::EMData::extract_plane(), EMAN::EMData::extractline(), EMAN::EMData::extractpoint(), EMAN::Util::extractpoint2(), EMAN::EMData::get_pixel_conv(), EMAN::Util::get_pixel_conv_new(), EMAN::Util::get_pixel_conv_new_background(), EMAN::EMData::rot_scale_conv(), and EMAN::EMData::rot_scale_conv7().

00438                 {

int EMAN::Util::KaiserBessel::get_window_size (  )  const [inline]

Return the size of the I0 window.

Definition at line 315 of file util.h.

Referenced by EMAN::EMData::extract_plane(), EMAN::EMData::extractline(), EMAN::EMData::extractpoint(), EMAN::EMData::get_pixel_conv(), EMAN::Util::get_pixel_conv_new(), EMAN::Util::get_pixel_conv_new_background(), EMAN::EMData::rot_scale_conv(), EMAN::EMData::rot_scale_conv7(), EMAN::EMData::rot_scale_conv_new(), and EMAN::EMData::rot_scale_conv_new_background().

00438 {

kbsinh_win EMAN::Util::KaiserBessel::get_kbsinh_win (  )  [inline]

Sinh window function object factory.

Definition at line 327 of file util.h.

00438                 {

kbi0_win EMAN::Util::KaiserBessel::get_kbi0_win (  )  [inline]

I0 window function object factory.

Definition at line 341 of file util.h.

00438                 {

Member Data Documentation

float EMAN::Util::KaiserBessel::alpha [protected]

Definition at line 274 of file util.h.

Referenced by KaiserBessel().

float EMAN::Util::KaiserBessel::v [protected]

Definition at line 274 of file util.h.

Referenced by KaiserBessel().

float EMAN::Util::KaiserBessel::r [protected]

Definition at line 274 of file util.h.

Referenced by KaiserBessel().

int EMAN::Util::KaiserBessel::N [protected]

Kaiser-Bessel parameters.

Definition at line 275 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), and build_I0table().

int EMAN::Util::KaiserBessel::K [protected]

size in Ix-space

Definition at line 276 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), build_I0table(), and KaiserBessel().

float EMAN::Util::KaiserBessel::vtable [protected]

I0 window size.

Definition at line 277 of file util.h.

Referenced by KaiserBessel().

int EMAN::Util::KaiserBessel::ntable [protected]

table I0 non-zero domain maximum

Definition at line 278 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), build_I0table(), and I0table_maxerror().

vector<float> EMAN::Util::KaiserBessel::i0table [protected]

Definition at line 279 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), build_I0table(), and I0table_maxerror().

float EMAN::Util::KaiserBessel::dtable [protected]

Definition at line 280 of file util.h.

float EMAN::Util::KaiserBessel::alphar [protected]

table spacing

Definition at line 281 of file util.h.

Referenced by KaiserBessel(), EMAN::Util::FakeKaiserBessel::sinhwin(), and sinhwin().

float EMAN::Util::KaiserBessel::fac [protected]

alpha*r

Definition at line 282 of file util.h.

Referenced by KaiserBessel(), EMAN::Util::FakeKaiserBessel::sinhwin(), and sinhwin().

float EMAN::Util::KaiserBessel::vadjust [protected]

2*pi*alpha*r*v

Definition at line 283 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), build_I0table(), EMAN::Util::FakeKaiserBessel::i0win(), i0win(), and KaiserBessel().

float EMAN::Util::KaiserBessel::facadj [protected]

Definition at line 284 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), build_I0table(), EMAN::Util::FakeKaiserBessel::i0win(), i0win(), and KaiserBessel().

float EMAN::Util::KaiserBessel::fltb [protected]

Tabulate I0 window for speed.

Definition at line 286 of file util.h.

Referenced by EMAN::Util::FakeKaiserBessel::build_I0table(), and build_I0table().

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