EMAN::PhaseCmp Class Reference

Amplitude weighted mean phase difference (radians) with optional SNR weight. More...

#include <cmp.h>

Inheritance diagram for EMAN::PhaseCmp:

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Collaboration diagram for EMAN::PhaseCmp:

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List of all members.

Public Member Functions
float	cmp (EMData *image, EMData *with) const
	To compare 'image' with another image passed in through its parameters.
string	get_name () const
	Get the Cmp's name.
string	get_desc () const
TypeDict	get_param_types () const
	Get Cmp parameter information in a dictionary.
Static Public Member Functions
static Cmp *	NEW ()

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Detailed Description

Amplitude weighted mean phase difference (radians) with optional SNR weight.

SNR should be an array as returned by ctfcurve() 'with' should be the less noisy image, since it's amplitudes will be used to weight the phase residual. 2D only.

Use Phase Residual as a measure of similarity Differential phase residual (DPR) is a measure of statistical dependency between two averages, computed over rings in Fourier space as a function of ring radius (= spatial frequency, or resolution)

Definition at line 409 of file cmp.h.

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Member Function Documentation

float PhaseCmp::cmp	(	EMData *	image,
		EMData *	with
	)			const [virtual]

To compare 'image' with another image passed in through its parameters.

An optional transformation may be used to transform the 2 images.

Parameters:

	image	The first image to be compared.
	with	The second image to be comppared.

Returns:

The comparison result. Smaller better by default

Implements EMAN::Cmp.

Definition at line 722 of file cmp.cpp.

References EMAN::Util::angle_sub_2pi(), EMAN::Ctf::CTFOS, EMAN::EMData::do_fft(), ENTERFUNC, EXITFUNC, EMAN::EMData::get_const_data(), EMAN::EMData::get_xsize(), EMAN::EMData::get_ysize(), EMAN::EMData::get_zsize(), EMAN::Util::hypot_fast(), norm(), ny, EMAN::EMData::ri2ap(), EMAN::Util::round(), sqrt(), EMAN::Cmp::validate_input_args(), x, and y.

{
        ENTERFUNC;

#ifdef EMAN2_USING_CUDA
        if (image->gpu_operation_preferred()) {
//              cout << "Cuda cmp" << endl;
                EXITFUNC;
                return cuda_cmp(image,with);
        }
#endif
        validate_input_args(image, with);

        static float *dfsnr = 0;
        static int nsnr = 0;

//      if (image->get_zsize() > 1) {
//              throw ImageDimensionException("2D only");
//      }

        //int nx = image->get_xsize();
        int ny = image->get_ysize();
        //int nz = image->get_zsize();

        int np = (int) ceil(Ctf::CTFOS * sqrt(2.0f) * ny / 2) + 2;

        if (nsnr != np) {
                nsnr = np;
                dfsnr = (float *) realloc(dfsnr, np * sizeof(float));

                //float w = Util::square(nx / 8.0f); // <- Not used currently

                for (int i = 0; i < np; i++) {
//                      float x2 = Util::square(i / (float) Ctf::CTFOS);
//                      dfsnr[i] = (1.0f - exp(-x2 / 4.0f)) * exp(-x2 / w);
                        float x2 = 10.0f*i/np;
                        dfsnr[i] = x2 * exp(-x2);
                }

//              Util::save_data(0, 1.0f / Ctf::CTFOS, dfsnr, np, "filt.txt");
        }

        EMData *image_fft = image->do_fft();
        image_fft->ri2ap();
        EMData *with_fft = with->do_fft();
        with_fft->ri2ap();

        const float *const image_fft_data = image_fft->get_const_data();
        const float *const with_fft_data = with_fft->get_const_data();
        double sum = 0;
        double norm = FLT_MIN;
        size_t i = 0;

        for (int z = 0; z < image_fft->get_zsize(); ++z){
                for (int y = 0; y < image_fft->get_ysize(); ++y) {
                        for (int x = 0; x < image_fft->get_xsize(); x += 2) {
                                int r;
//                              if ( nz == 1 ) {
                                        if (y<ny/2) r = Util::round(Util::hypot_fast(x / 2, y) * Ctf::CTFOS);
                                        else r = Util::round(Util::hypot_fast(x / 2, y-ny) * Ctf::CTFOS);

                                float a = dfsnr[r] * with_fft_data[i];
//                              cout << a << " " << Util::angle_sub_2pi(image_fft_data[i + 1], with_fft_data[i + 1]) << " " <<image_fft_data[i + 1] << " " << with_fft_data[i + 1] << endl;
                                sum += Util::angle_sub_2pi(image_fft_data[i + 1], with_fft_data[i + 1]) * a;
                                norm += a;
                                i += 2;
                        }
                }
        }
        EXITFUNC;

        if( image_fft )
        {
                delete image_fft;
                image_fft = 0;
        }
        if( with_fft )
        {
                delete with_fft;
                with_fft = 0;
        }
#if 0
        return (1.0f - sum / norm);
#endif
        return (float)(sum / norm);
}

string EMAN::PhaseCmp::get_name

(

)

const [inline, virtual]

Get the Cmp's name.

Each Cmp is identified by a unique name.

Returns:

The Cmp's name.

Implements EMAN::Cmp.

Definition at line 414 of file cmp.h.

                {
                        return "phase";
                }

string EMAN::PhaseCmp::get_desc

(

)

const [inline, virtual]

Implements EMAN::Cmp.

Definition at line 419 of file cmp.h.

                {
                        return "Mean phase difference";
                }

static Cmp* EMAN::PhaseCmp::NEW

(

)

[inline, static]

Definition at line 424 of file cmp.h.

                {
                        return new PhaseCmp();
                }

TypeDict EMAN::PhaseCmp::get_param_types

(

)

const [inline, virtual]

Get Cmp parameter information in a dictionary.

Each parameter has one record in the dictionary. Each record contains its name, data-type, and description.

Returns:

A dictionary containing the parameter info.

Implements EMAN::Cmp.

Definition at line 429 of file cmp.h.

                {
                        TypeDict d;
                        return d;
                }

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

• cmp.h
• cmp.cpp