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EMAN::ModelHelixProcessor Class Reference

#include <processor.h>

Inheritance diagram for EMAN::ModelHelixProcessor:

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Collaboration diagram for EMAN::ModelHelixProcessor:

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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 9542 of file processor.cpp.

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

09543               : modified from EMAN1 Cylinder.C by Wen Jiang
09544 {
09545         // r in angstrom
09546         double ret = 0;//iterations ==> rounding is problematic with float types if 15 < r < 20 and really bad if 20 < r < 30
09547         if (type == 0) { // pure Gaussian falloff
09548                 r /= 2;
09549                 ret = exp(-r * r);
09550         } else if (type == 1) { // pure Gaussian falloff + negative dip, so mean is 0
09551                 r /= 2;
09552                 ret = (1 - r * r / 4) * exp(-r * r / 4);
09553         } else if (type == 2) {
09554                 // polynomial fitting to the radial profile of real helix density
09555                 // f=a0*x^n+a1+x^(n-1)+ ... +a[n-1]*x+an
09556                 //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};
09557 
09558                 // now the fitting to the original profile
09559                 if (r >= 12.2)
09560                         return 0; //We don't want that part of the polynomial --> goes way below zero
09561                 static float an[15] = { -3.9185246832229140e-16f,
09562                                 3.3957205298900993e-14f, 2.0343351971222658e-12f,
09563                                 -4.4935965816879751e-10f, 3.0668169835080933e-08f,
09564                                 -1.1904544689091790e-06f, 2.9753088549414953e-05f,
09565                                 -4.9802112876220150e-04f, 5.5900917825309360e-03f,
09566                                 -4.0823714462925299e-02f, 1.8021733669148599e-01f,
09567                                 -4.0992557296268717e-01f, 3.3980328566901458e-01f,
09568                                 -3.6062024812411908e-01f, 1.0000000000000000e+00f };
09569 
09570                 ret = an[0];
09571                 for (int i = 1; i < 15; i++) {
09572                         ret = ret * r + an[i];
09573                 }
09574         }
09575         return (float)ret;
09576 }


The documentation for this class was generated from the following files:
Generated on Mon May 2 13:30:57 2011 for EMAN2 by  doxygen 1.3.9.1