Commit 7205d63d authored by Claudio Gheller's avatar Claudio Gheller
Browse files

Precalculated Gaussian Kernel added

parent 2d16e4a0

w-stacking.cu

+23 −2
Original line number Diff line number Diff line
@@ -22,6 +22,22 @@ gauss_kernel_norm(double norm, double std22, double u_dist, double v_dist) 
     return conv_weight;

}



void makeGaussKernel(double * kernel,

		     int KernelLen,

		     double std22)

{



  double norm = std22/PI;

  int n = KernelLen, mid = n / 2;

  for (int i = 0; i != mid + 1; i++) {

      double term = (double)i / mid;

      kernel[mid + i] = sqrt(norm) * exp(-(term*term)*std22);

  }



  for (int i = 0; i != mid; i++) kernel[i] = kernel[n - 1 - i];



}



// Kaiser-Bessel Kernel: it is adapted from WSClean

double bessel0(double x, double precision) {

  // Calculate I_0 = SUM of m 0 -> inf [ (x/2)^(2m) ]
@@ -188,6 +204,8 @@ void wstack( 
    double std = 1.0;

    double std22 = 1.0/(2.0*std*std);

    double norm = std22/PI;

    double * convkernel = malloc(w_support*sizeof(*convkernel));

    makeGaussKernel(convkernel,w_support,std22);

    

    // Loop over visibilities.

// Switch between CUDA and GPU versions
@@ -309,11 +327,14 @@ void wstack( 


            for (j = jmin; j <= jmax; j++)

            {

		int jKer = (int)j-pos_u+KernelLen;

		int kKer = (int)k-pos_v+KernelLen;

                double u_dist = (double)j+0.5 - pos_u;

		long iKer = 2 * (j + k*grid_size_x + grid_w*grid_size_x*grid_size_y);





		double conv_weight = gauss_kernel_norm(norm,std22,u_dist,v_dist);

		//double conv_weight = gauss_kernel_norm(norm,std22,u_dist,v_dist);

		double conv_weight = convkernel[jKer]*convkernel[kKer];

		// Loops over frequencies and polarizations

		double add_term_real = 0.0;

		double add_term_img = 0.0;

w-stacking-fftw.c

+2 −2

File changed.

Contains only whitespace changes.