Main Page | Modules | Namespace List | Class Hierarchy | Alphabetical List | Class List | Directories | File List | Namespace Members | Class Members | File Members

EMAN::ModelHelixProcessor Class Reference

#include <processor.h>

Inheritance diagram for EMAN::ModelHelixProcessor:

Inheritance graph
[legend]
Collaboration diagram for EMAN::ModelHelixProcessor:

Collaboration graph
[legend]
List of all members.

Protected Member Functions

float radprofile (float r, int type)

Member Function Documentation

float ModelHelixProcessor::radprofile float  r,
int  type
[protected]
 

Definition at line 9747 of file processor.cpp.

Referenced by EMAN::ApplyPolynomialProfileToHelix::process_inplace(), and EMAN::ModelEMCylinderProcessor::process_inplace().

09748               : modified from EMAN1 Cylinder.C by Wen Jiang
09749 {
09750         // r in angstrom
09751         double ret = 0;//iterations ==> rounding is problematic with float types if 15 < r < 20 and really bad if 20 < r < 30
09752         if (type == 0) { // pure Gaussian falloff
09753                 r /= 2;
09754                 ret = exp(-r * r);
09755         } else if (type == 1) { // pure Gaussian falloff + negative dip, so mean is 0
09756                 r /= 2;
09757                 ret = (1 - r * r / 4) * exp(-r * r / 4);
09758         } else if (type == 2) {
09759                 // polynomial fitting to the radial profile of real helix density
09760                 // f=a0*x^n+a1+x^(n-1)+ ... +a[n-1]*x+an
09761                 //float an[11]={2.847024584977009e-10,-3.063997224364090e-08,1.418801040660860e-06,-3.678676414383996e-05,5.804871622801710e-04,-5.640340018430164e-03,3.208802421493864e-02,-9.068475313823952e-02,7.097329559749284e-02,-9.993347339658298e-02,1.000000000000000e+00};
09762 
09763                 // now the fitting to the original profile
09764                 if (r >= 12.2)
09765                         return 0; //We don't want that part of the polynomial --> goes way below zero
09766                 static float an[15] = { -3.9185246832229140e-16f,
09767                                 3.3957205298900993e-14f, 2.0343351971222658e-12f,
09768                                 -4.4935965816879751e-10f, 3.0668169835080933e-08f,
09769                                 -1.1904544689091790e-06f, 2.9753088549414953e-05f,
09770                                 -4.9802112876220150e-04f, 5.5900917825309360e-03f,
09771                                 -4.0823714462925299e-02f, 1.8021733669148599e-01f,
09772                                 -4.0992557296268717e-01f, 3.3980328566901458e-01f,
09773                                 -3.6062024812411908e-01f, 1.0000000000000000e+00f };
09774 
09775                 ret = an[0];
09776                 for (int i = 1; i < 15; i++) {
09777                         ret = ret * r + an[i];
09778                 }
09779         }
09780         return (float)ret;
09781 }


The documentation for this class was generated from the following files:
Generated on Mon Aug 13 13:42:32 2012 for EMAN2 by  doxygen 1.3.9.1