blobtype Struct Reference

#include <blobs.h>

Public Attributes
double	radius
	Spatial radius in Universal System units. More...
int	order
	Derivation order and Bessel function order. More...
double	alpha
	Smoothness parameter. More...

Detailed Description

Blob definition. The blob is a space limited function (click here for a theoretical explanation) which is used as basis function for the ART reconstructions. There are several parameters which define the shape of the blob. The following structure holds all needed information for a blob, a variable can be of this type and it is passed to the different functions containing all we need to know about the blob. As a type definition, we can work with several kind of blobs in the same program at the same time.

The common way of defining a blob is as follows:

struct blobtype blob;                  // Definition of the blob
blob.radius = 2;                       // Blob radius in voxels
blob.order  = 2;                       // Order of the Bessel function
blob.alpha  = 3.6;                     // Smoothness parameter

Sometimes it is useful to plot any quantity related to the blobs. In the following example you have how to plot their Fourier transform in the continuous frequency space.

#include <Reconstruction/blobs.hh>
#include <XmippData/xmippArgs.hh>

int main(int argc, char **argv) {
   struct blobtype blob;                  // Definition of the blob
   blob.radius = 2;                       // Blob radius in voxels
   blob.order  = 2;                       // Order of the Bessel function
   blob.alpha  = textToFloat(argv[1]);    // Smoothness parameter

   double M=blob_Fourier_val (0, blob);
   for (double w=0; w<=2; w += 0.05)
      std::cout << w << " " <<  blob_Fourier_val (w, blob)/M << std::endl;
   return 0;
}

Definition at line 112 of file blobs.h.

Member Data Documentation

alpha

double blobtype::alpha

Smoothness parameter.

Definition at line 121 of file blobs.h.

order

int blobtype::order

Derivation order and Bessel function order.

Definition at line 118 of file blobs.h.

radius

double blobtype::radius

Spatial radius in Universal System units.

Definition at line 115 of file blobs.h.

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The documentation for this struct was generated from the following file:

• xmipp/libraries/data/blobs.h