gridder_cxx.h 40.2 KB
Newer Older
Martin Reinecke's avatar
Martin Reinecke committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
#ifndef GRIDDER_CXX_H
#define GRIDDER_CXX_H

/*
 *  This file is part of nifty_gridder.
 *
 *  nifty_gridder is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  nifty_gridder is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with nifty_gridder; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/* Copyright (C) 2019 Max-Planck-Society
   Author: Martin Reinecke */

#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <array>

#include "mr_util/error_handling.h"
#include "mr_util/fft.h"
#include "mr_util/threading.h"
#include "mr_util/useful_macros.h"
#include "mr_util/mav.h"
#include "mr_util/gl_integrator.h"

#if defined(__GNUC__)
#define ALIGNED(align) __attribute__ ((aligned(align)))
#else
#define ALIGNED(align)
#endif

namespace gridder {

namespace detail {

using namespace std;
using namespace mr;

template<size_t ndim> void checkShape
  (const array<size_t, ndim> &shp1, const array<size_t, ndim> &shp2)
  {
  for (size_t i=0; i<ndim; ++i)
    MR_assert(shp1[i]==shp2[i], "shape mismatch");
  }

template<typename T> inline T fmod1 (T v)
  { return v-floor(v); }

//
// Start of real gridder functionality
//

template<typename T> void complex2hartley
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
67
  (const mav<complex<T>, 2> &grid, mav<T,2> &grid2, size_t nthreads)
Martin Reinecke's avatar
Martin Reinecke committed
68
69
70
71
72
73
74
75
76
77
78
79
  {
  checkShape(grid.shape(), grid2.shape());
  size_t nu=grid.shape(0), nv=grid.shape(1);

  execStatic(nu, nthreads, 0, [&](Scheduler &sched)
    {
    while (auto rng=sched.getNext()) for(auto u=rng.lo; u<rng.hi; ++u)
      {
      size_t xu = (u==0) ? 0 : nu-u;
      for (size_t v=0; v<nv; ++v)
        {
        size_t xv = (v==0) ? 0 : nv-v;
Martin Reinecke's avatar
Martin Reinecke committed
80
81
        grid2.v(u,v) = T(0.5)*(grid( u, v).real()+grid( u, v).imag()+
                               grid(xu,xv).real()-grid(xu,xv).imag());
Martin Reinecke's avatar
Martin Reinecke committed
82
83
84
85
86
87
        }
      }
    });
  }

template<typename T> void hartley2complex
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
88
  (const mav<T,2> &grid, mav<complex<T>,2> &grid2, size_t nthreads)
Martin Reinecke's avatar
Martin Reinecke committed
89
90
91
92
93
94
95
96
97
98
99
100
101
102
  {
  checkShape(grid.shape(), grid2.shape());
  size_t nu=grid.shape(0), nv=grid.shape(1);

  execStatic(nu, nthreads, 0, [&](Scheduler &sched)
    {
    while (auto rng=sched.getNext()) for(auto u=rng.lo; u<rng.hi; ++u)
      {
      size_t xu = (u==0) ? 0 : nu-u;
      for (size_t v=0; v<nv; ++v)
        {
        size_t xv = (v==0) ? 0 : nv-v;
        T v1 = T(0.5)*grid( u, v);
        T v2 = T(0.5)*grid(xu,xv);
Martin Reinecke's avatar
Martin Reinecke committed
103
        grid2.v(u,v) = std::complex<T>(v1+v2, v1-v2);
Martin Reinecke's avatar
Martin Reinecke committed
104
105
106
107
108
        }
      }
    });
  }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
109
110
template<typename T> void hartley2_2D(const mav<T,2> &in,
  mav<T,2> &out, size_t nthreads)
Martin Reinecke's avatar
Martin Reinecke committed
111
112
113
  {
  checkShape(in.shape(), out.shape());
  size_t nu=in.shape(0), nv=in.shape(1);
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
114
115
  fmav<T> fin(in), fout(out);
  r2r_separable_hartley(fin, fout, {0,1}, T(1), nthreads);
Martin Reinecke's avatar
Martin Reinecke committed
116
117
118
119
120
  execStatic((nu+1)/2-1, nthreads, 0, [&](Scheduler &sched)
    {
    while (auto rng=sched.getNext()) for(auto i=rng.lo+1; i<rng.hi+1; ++i)
      for(size_t j=1; j<(nv+1)/2; ++j)
         {
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
121
122
123
124
         T a = out(i,j);
         T b = out(nu-i,j);
         T c = out(i,nv-j);
         T d = out(nu-i,nv-j);
Martin Reinecke's avatar
Martin Reinecke committed
125
126
127
128
         out.v(i,j) = T(0.5)*(a+b+c-d);
         out.v(nu-i,j) = T(0.5)*(a+b+d-c);
         out.v(i,nv-j) = T(0.5)*(a+c+d-b);
         out.v(nu-i,nv-j) = T(0.5)*(b+c+d-a);
Martin Reinecke's avatar
Martin Reinecke committed
129
130
131
132
         }
     });
  }

Martin Reinecke's avatar
Martin Reinecke committed
133

Martin Reinecke's avatar
Martin Reinecke committed
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
class ES_Kernel
  {
  private:
    static constexpr double pi = 3.141592653589793238462643383279502884197;
    double beta;
    int p;
    vector<double> x, wgt, psi;
    size_t supp;

  public:
    ES_Kernel(size_t supp_, double ofactor, size_t nthreads)
      : beta(get_beta(supp_,ofactor)*supp_), p(int(1.5*supp_+2)), supp(supp_)
      {
      GL_Integrator integ(2*p,nthreads);
      x = integ.coordsSymmetric();
      wgt = integ.weightsSymmetric();
      psi=x;
      for (auto &v:psi)
        v=operator()(v);
      }
    ES_Kernel(size_t supp_, size_t nthreads)
      : ES_Kernel(supp_, 2., nthreads){}

Martin Reinecke's avatar
Martin Reinecke committed
157
    double operator()(double v) const { return (v*v>1.) ? 0. : exp(beta*(sqrt(1.-v*v)-1.)); }
Martin Reinecke's avatar
Martin Reinecke committed
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
    /* Compute correction factors for the ES gridding kernel
       This implementation follows eqs. (3.8) to (3.10) of Barnett et al. 2018 */
    double corfac(double v) const
      {
      double tmp=0;
      for (int i=0; i<p; ++i)
        tmp += wgt[i]*psi[i]*cos(pi*supp*v*x[i]);
      return 2./(supp*tmp);
      }
    static double get_beta(size_t supp, double ofactor=2)
      {
      MR_assert((supp>=2) && (supp<=15), "unsupported support size");
      if (ofactor>=2)
        {
        static const vector<double> opt_beta {-1, 0.14, 1.70, 2.08, 2.205, 2.26,
          2.29, 2.307, 2.316, 2.3265, 2.3324, 2.282, 2.294, 2.304, 2.3138, 2.317};
        MR_assert(supp<opt_beta.size(), "bad support size");
        return opt_beta[supp];
        }
Martin Reinecke's avatar
Martin Reinecke committed
177
      if (ofactor>=1.175)
Martin Reinecke's avatar
Martin Reinecke committed
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
        {
        // empirical, but pretty accurate approximation
        static const array<double,16> betacorr{0,0,-0.51,-0.21,-0.1,-0.05,-0.025,-0.0125,0,0,0,0,0,0,0,0};
        auto x0 = 1./(2*ofactor);
        auto bcstrength=1.+(x0-0.25)*2.5;
        return 2.32+bcstrength*betacorr[supp]+(0.25-x0)*3.1;
        }
      MR_fail("oversampling factor is too small");
      }

    static size_t get_supp(double epsilon, double ofactor=2)
      {
      double epssq = epsilon*epsilon;
      if (ofactor>=2)
        {
        static const vector<double> maxmaperr { 1e8, 0.19, 2.98e-3, 5.98e-5,
          1.11e-6, 2.01e-8, 3.55e-10, 5.31e-12, 8.81e-14, 1.34e-15, 2.17e-17,
          2.12e-19, 2.88e-21, 3.92e-23, 8.21e-25, 7.13e-27 };

        for (size_t i=2; i<maxmaperr.size(); ++i)
          if (epssq>maxmaperr[i]) return i;
        MR_fail("requested epsilon too small - minimum is 1e-13");
        }
Martin Reinecke's avatar
Martin Reinecke committed
201
      if (ofactor>=1.175)
Martin Reinecke's avatar
Martin Reinecke committed
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
        {
        for (size_t w=2; w<16; ++w)
          {
          auto estimate = 12*exp(-2.*w*ofactor); // empirical, not very good approximation
          if (epssq>estimate) return w;
          }
        MR_fail("requested epsilon too small");
        }
      MR_fail("oversampling factor is too small");
      }
  };

/* Compute correction factors for the ES gridding kernel
   This implementation follows eqs. (3.8) to (3.10) of Barnett et al. 2018 */
vector<double> correction_factors(size_t n, double ofactor, size_t nval, size_t supp,
  size_t nthreads)
  {
  ES_Kernel kernel(supp, ofactor, nthreads);
  vector<double> res(nval);
  double xn = 1./n;
  execStatic(nval, nthreads, 0, [&](Scheduler &sched)
    {
    while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
      res[i] = kernel.corfac(i*xn);
    });
  return res;
  }

using idx_t = uint32_t;

struct RowChan
  {
  idx_t row, chan;
  };

struct UVW
  {
  double u, v, w;
  UVW() {}
  UVW(double u_, double v_, double w_) : u(u_), v(v_), w(w_) {}
  UVW operator* (double fct) const
    { return UVW(u*fct, v*fct, w*fct); }
  void Flip() { u=-u; v=-v; w=-w; }
  bool FixW()
    {
    bool flip = w<0;
    if (flip) Flip();
    return flip;
    }
  };

class Baselines
  {
  protected:
    vector<UVW> coord;
    vector<double> f_over_c;
    idx_t nrows, nchan;
    idx_t shift, mask;

  public:
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
262
263
    template<typename T> Baselines(const mav<T,2> &coord_,
      const mav<T,1> &freq, bool negate_v=false)
Martin Reinecke's avatar
Martin Reinecke committed
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
      {
      constexpr double speedOfLight = 299792458.;
      MR_assert(coord_.shape(1)==3, "dimension mismatch");
      auto hugeval = size_t(~(idx_t(0)));
      MR_assert(coord_.shape(0)<hugeval, "too many entries in MS");
      MR_assert(coord_.shape(1)<hugeval, "too many entries in MS");
      MR_assert(coord_.size()<hugeval, "too many entries in MS");
      nrows = coord_.shape(0);
      nchan = freq.shape(0);
      shift=0;
      while((idx_t(1)<<shift)<nchan) ++shift;
      mask=(idx_t(1)<<shift)-1;
      MR_assert(nrows*(mask+1)<hugeval, "too many entries in MS");
      f_over_c.resize(nchan);
      for (size_t i=0; i<nchan; ++i)
        {
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
280
        MR_assert(freq(i)>0, "negative channel frequency encountered");
Martin Reinecke's avatar
Martin Reinecke committed
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
        f_over_c[i] = freq(i)/speedOfLight;
        }
      coord.resize(nrows);
      if (negate_v)
        for (size_t i=0; i<coord.size(); ++i)
          coord[i] = UVW(coord_(i,0), -coord_(i,1), coord_(i,2));
      else
        for (size_t i=0; i<coord.size(); ++i)
          coord[i] = UVW(coord_(i,0), coord_(i,1), coord_(i,2));
      }

    RowChan getRowChan(idx_t index) const
      { return RowChan{index>>shift, index&mask}; }

    UVW effectiveCoord(const RowChan &rc) const
      { return coord[rc.row]*f_over_c[rc.chan]; }
    UVW effectiveCoord(idx_t index) const
      { return effectiveCoord(getRowChan(index)); }
    size_t Nrows() const { return nrows; }
    size_t Nchannels() const { return nchan; }
    idx_t getIdx(idx_t irow, idx_t ichan) const
      { return ichan+(irow<<shift); }
  };

class GridderConfig
  {
  protected:
    size_t nx_dirty, ny_dirty, nu, nv;
    double ofactor, eps, psx, psy;
    size_t supp, nsafe;
    double beta;
    size_t nthreads;
    double ushift, vshift;
    int maxiu0, maxiv0;

    template<typename T> complex<T> wscreen(T x, T y, T w, bool adjoint) const
      {
      constexpr T pi = T(3.141592653589793238462643383279502884197);
      T tmp = 1-x-y;
      if (tmp<=0) return 1; // no phase factor beyond the horizon
      T nm1 = (-x-y)/(sqrt(tmp)+1); // more accurate form of sqrt(1-x-y)-1
      T phase = 2*pi*w*nm1;
      if (adjoint) phase *= -1;
      return complex<T>(cos(phase), sin(phase));
      }

  public:
    GridderConfig(size_t nxdirty, size_t nydirty, size_t nu_, size_t nv_,
      double epsilon, double pixsize_x, double pixsize_y, size_t nthreads_)
      : nx_dirty(nxdirty), ny_dirty(nydirty), nu(nu_), nv(nv_),
        ofactor(min(double(nu)/nxdirty, double(nv)/nydirty)),
        eps(epsilon),
        psx(pixsize_x), psy(pixsize_y),
        supp(ES_Kernel::get_supp(epsilon, ofactor)), nsafe((supp+1)/2),
        beta(ES_Kernel::get_beta(supp, ofactor)*supp),
        nthreads(nthreads_),
        ushift(supp*(-0.5)+1+nu), vshift(supp*(-0.5)+1+nv),
        maxiu0((nu+nsafe)-supp), maxiv0((nv+nsafe)-supp)
      {
      MR_assert(nu>=2*nsafe, "nu too small");
      MR_assert(nv>=2*nsafe, "nv too small");
      MR_assert((nx_dirty&1)==0, "nx_dirty must be even");
      MR_assert((ny_dirty&1)==0, "ny_dirty must be even");
      MR_assert((nu&1)==0, "nu must be even");
      MR_assert((nv&1)==0, "nv must be even");
      MR_assert(epsilon>0, "epsilon must be positive");
      MR_assert(pixsize_x>0, "pixsize_x must be positive");
      MR_assert(pixsize_y>0, "pixsize_y must be positive");
Martin Reinecke's avatar
Martin Reinecke committed
349
350
      MR_assert(ofactor>=1.175,
        "oversampling factor too small (>=1.2 recommended)");
Martin Reinecke's avatar
Martin Reinecke committed
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
      }
    GridderConfig(size_t nxdirty, size_t nydirty,
      double epsilon, double pixsize_x, double pixsize_y, size_t nthreads_)
      : GridderConfig(nxdirty, nydirty, max<size_t>(30,2*nxdirty),
                      max<size_t>(30,2*nydirty), epsilon, pixsize_x,
                      pixsize_y, nthreads_) {}
    size_t Nxdirty() const { return nx_dirty; }
    size_t Nydirty() const { return ny_dirty; }
    double Epsilon() const { return eps; }
    double Pixsize_x() const { return psx; }
    double Pixsize_y() const { return psy; }
    size_t Nu() const { return nu; }
    size_t Nv() const { return nv; }
    size_t Supp() const { return supp; }
    size_t Nsafe() const { return nsafe; }
    double Beta() const { return beta; }
    size_t Nthreads() const { return nthreads; }
    double Ofactor() const{ return ofactor; }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
370
371
    template<typename T> void grid2dirty_post(mav<T,2> &tmav,
      mav<T,2> &dirty) const
Martin Reinecke's avatar
Martin Reinecke committed
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
      {
      checkShape(dirty.shape(), {nx_dirty,ny_dirty});
      auto cfu = correction_factors(nu, ofactor, nx_dirty/2+1, supp, nthreads);
      auto cfv = correction_factors(nv, ofactor, ny_dirty/2+1, supp, nthreads);
      execStatic(nx_dirty, nthreads, 0, [&](Scheduler &sched)
        {
        while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
          {
          int icfu = abs(int(nx_dirty/2)-int(i));
          for (size_t j=0; j<ny_dirty; ++j)
            {
            int icfv = abs(int(ny_dirty/2)-int(j));
            size_t i2 = nu-nx_dirty/2+i;
            if (i2>=nu) i2-=nu;
            size_t j2 = nv-ny_dirty/2+j;
            if (j2>=nv) j2-=nv;
            // FIXME: for some reason g++ warns about double-to-float conversion
            // here, even though there is an explicit cast...
Martin Reinecke's avatar
Martin Reinecke committed
390
            dirty.v(i,j) = tmav(i2,j2)*T(cfu[icfu]*cfv[icfv]);
Martin Reinecke's avatar
Martin Reinecke committed
391
392
393
394
395
            }
          }
        });
      }
    template<typename T> void grid2dirty_post2(
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
396
      mav<complex<T>,2> &tmav, mav<T,2> &dirty, T w) const
Martin Reinecke's avatar
Martin Reinecke committed
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
      {
      checkShape(dirty.shape(), {nx_dirty,ny_dirty});
      double x0 = -0.5*nx_dirty*psx,
             y0 = -0.5*ny_dirty*psy;
      execStatic(nx_dirty/2+1, nthreads, 0, [&](Scheduler &sched)
        {
        while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
          {
          T fx = T(x0+i*psx);
          fx *= fx;
          for (size_t j=0; j<=ny_dirty/2; ++j)
            {
            T fy = T(y0+j*psy);
            auto ws = wscreen(fx, fy*fy, w, true);
            size_t ix = nu-nx_dirty/2+i;
            if (ix>=nu) ix-=nu;
            size_t jx = nv-ny_dirty/2+j;
            if (jx>=nv) jx-=nv;
Martin Reinecke's avatar
Martin Reinecke committed
415
            dirty.v(i,j) += (tmav(ix,jx)*ws).real(); // lower left
Martin Reinecke's avatar
Martin Reinecke committed
416
417
418
419
420
421
422
            size_t i2 = nx_dirty-i, j2 = ny_dirty-j;
            size_t ix2 = nu-nx_dirty/2+i2;
            if (ix2>=nu) ix2-=nu;
            size_t jx2 = nv-ny_dirty/2+j2;
            if (jx2>=nv) jx2-=nv;
            if ((i>0)&&(i<i2))
              {
Martin Reinecke's avatar
Martin Reinecke committed
423
              dirty.v(i2,j) += (tmav(ix2,jx)*ws).real(); // lower right
Martin Reinecke's avatar
Martin Reinecke committed
424
              if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
425
                dirty.v(i2,j2) += (tmav(ix2,jx2)*ws).real(); // upper right
Martin Reinecke's avatar
Martin Reinecke committed
426
427
              }
            if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
428
              dirty.v(i,j2) += (tmav(ix,jx2)*ws).real(); // upper left
Martin Reinecke's avatar
Martin Reinecke committed
429
430
431
432
433
            }
          }
        });
      }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
434
435
    template<typename T> void grid2dirty(const mav<T,2> &grid,
      mav<T,2> &dirty) const
Martin Reinecke's avatar
Martin Reinecke committed
436
437
      {
      checkShape(grid.shape(), {nu,nv});
438
      mav<T,2> tmav({nu,nv});
Martin Reinecke's avatar
Martin Reinecke committed
439
440
441
442
443
      hartley2_2D<T>(grid, tmav, nthreads);
      grid2dirty_post(tmav, dirty);
      }

    template<typename T> void grid2dirty_c_overwrite_wscreen_add
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
444
      (mav<complex<T>,2> &grid, mav<T,2> &dirty, T w) const
Martin Reinecke's avatar
Martin Reinecke committed
445
446
      {
      checkShape(grid.shape(), {nu,nv});
Martin Reinecke's avatar
Martin Reinecke committed
447
448
      fmav<complex<T>> inout(grid);
      c2c(inout, inout, {0,1}, BACKWARD, T(1), nthreads);
Martin Reinecke's avatar
Martin Reinecke committed
449
450
451
      grid2dirty_post2(grid, dirty, w);
      }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
452
453
    template<typename T> void dirty2grid_pre(const mav<T,2> &dirty,
      mav<T,2> &grid) const
Martin Reinecke's avatar
Martin Reinecke committed
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
      {
      checkShape(dirty.shape(), {nx_dirty, ny_dirty});
      checkShape(grid.shape(), {nu, nv});
      auto cfu = correction_factors(nu, ofactor, nx_dirty/2+1, supp, nthreads);
      auto cfv = correction_factors(nv, ofactor, ny_dirty/2+1, supp, nthreads);
      grid.fill(0);
      execStatic(nx_dirty, nthreads, 0, [&](Scheduler &sched)
        {
        while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
          {
          int icfu = abs(int(nx_dirty/2)-int(i));
          for (size_t j=0; j<ny_dirty; ++j)
            {
            int icfv = abs(int(ny_dirty/2)-int(j));
            size_t i2 = nu-nx_dirty/2+i;
            if (i2>=nu) i2-=nu;
            size_t j2 = nv-ny_dirty/2+j;
            if (j2>=nv) j2-=nv;
Martin Reinecke's avatar
Martin Reinecke committed
472
            grid.v(i2,j2) = dirty(i,j)*T(cfu[icfu]*cfv[icfv]);
Martin Reinecke's avatar
Martin Reinecke committed
473
474
475
476
            }
          }
        });
      }
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
477
478
    template<typename T> void dirty2grid_pre2(const mav<T,2> &dirty,
      mav<complex<T>,2> &grid, T w) const
Martin Reinecke's avatar
Martin Reinecke committed
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
      {
      checkShape(dirty.shape(), {nx_dirty, ny_dirty});
      checkShape(grid.shape(), {nu, nv});
      grid.fill(0);

      double x0 = -0.5*nx_dirty*psx,
             y0 = -0.5*ny_dirty*psy;
      execStatic(nx_dirty/2+1, nthreads, 0, [&](Scheduler &sched)
        {
        while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
          {
          T fx = T(x0+i*psx);
          fx *= fx;
          for (size_t j=0; j<=ny_dirty/2; ++j)
            {
            T fy = T(y0+j*psy);
            auto ws = wscreen(fx, fy*fy, w, false);
            size_t ix = nu-nx_dirty/2+i;
            if (ix>=nu) ix-=nu;
            size_t jx = nv-ny_dirty/2+j;
            if (jx>=nv) jx-=nv;
Martin Reinecke's avatar
Martin Reinecke committed
500
            grid.v(ix,jx) = dirty(i,j)*ws; // lower left
Martin Reinecke's avatar
Martin Reinecke committed
501
502
503
504
505
506
507
            size_t i2 = nx_dirty-i, j2 = ny_dirty-j;
            size_t ix2 = nu-nx_dirty/2+i2;
            if (ix2>=nu) ix2-=nu;
            size_t jx2 = nv-ny_dirty/2+j2;
            if (jx2>=nv) jx2-=nv;
            if ((i>0)&&(i<i2))
              {
Martin Reinecke's avatar
Martin Reinecke committed
508
              grid.v(ix2,jx) = dirty(i2,j)*ws; // lower right
Martin Reinecke's avatar
Martin Reinecke committed
509
              if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
510
                grid.v(ix2,jx2) = dirty(i2,j2)*ws; // upper right
Martin Reinecke's avatar
Martin Reinecke committed
511
512
              }
            if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
513
              grid.v(ix,jx2) = dirty(i,j2)*ws; // upper left
Martin Reinecke's avatar
Martin Reinecke committed
514
515
516
517
518
            }
          }
        });
      }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
519
520
    template<typename T> void dirty2grid(const mav<T,2> &dirty,
      mav<T,2> &grid) const
Martin Reinecke's avatar
Martin Reinecke committed
521
522
      {
      dirty2grid_pre(dirty, grid);
Martin Reinecke's avatar
Martin Reinecke committed
523
      hartley2_2D<T>(grid, grid, nthreads);
Martin Reinecke's avatar
Martin Reinecke committed
524
525
      }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
526
527
    template<typename T> void dirty2grid_c_wscreen(const mav<T,2> &dirty,
      mav<complex<T>,2> &grid, T w) const
Martin Reinecke's avatar
Martin Reinecke committed
528
529
      {
      dirty2grid_pre2(dirty, grid, w);
Martin Reinecke's avatar
Martin Reinecke committed
530
531
      fmav<complex<T>> inout(grid);
      c2c(inout, inout, {0,1}, FORWARD, T(1), nthreads);
Martin Reinecke's avatar
Martin Reinecke committed
532
533
534
535
536
537
538
539
540
541
      }

    void getpix(double u_in, double v_in, double &u, double &v, int &iu0, int &iv0) const
      {
      u=fmod1(u_in*psx)*nu;
      iu0 = min(int(u+ushift)-int(nu), maxiu0);
      v=fmod1(v_in*psy)*nv;
      iv0 = min(int(v+vshift)-int(nv), maxiv0);
      }

Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
542
    template<typename T> void apply_wscreen(const mav<complex<T>,2> &dirty,
Martin Reinecke's avatar
Martin Reinecke committed
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
      mav<complex<T>,2> &dirty2, double w, bool adjoint) const
      {
      checkShape(dirty.shape(), {nx_dirty, ny_dirty});
      checkShape(dirty2.shape(), {nx_dirty, ny_dirty});

      double x0 = -0.5*nx_dirty*psx,
             y0 = -0.5*ny_dirty*psy;
      execStatic(nx_dirty/2+1, nthreads, 0, [&](Scheduler &sched)
        {
        while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
          {
          T fx = T(x0+i*psx);
          fx *= fx;
          for (size_t j=0; j<=ny_dirty/2; ++j)
            {
            T fy = T(y0+j*psy);
            auto ws = wscreen(fx, fy*fy, T(w), adjoint);
            dirty2(i,j) = dirty(i,j)*ws; // lower left
            size_t i2 = nx_dirty-i, j2 = ny_dirty-j;
            if ((i>0)&&(i<i2))
              {
              dirty2(i2,j) = dirty(i2,j)*ws; // lower right
              if ((j>0)&&(j<j2))
                dirty2(i2,j2) = dirty(i2,j2)*ws; // upper right
              }
            if ((j>0)&&(j<j2))
              dirty2(i,j2) = dirty(i,j2)*ws; // upper left
            }
          }
        });
      }
  };

constexpr int logsquare=4;

template<typename T, typename T2=complex<T>> class Helper
  {
  private:
    const GridderConfig &gconf;
    int nu, nv, nsafe, supp;
    T beta;
    const T2 *grid_r;
    T2 *grid_w;
    int su, sv;
    int iu0, iv0; // start index of the current visibility
    int bu0, bv0; // start index of the current buffer

    vector<T2> rbuf, wbuf;
    bool do_w_gridding;
    double w0, xdw;
    size_t nexp;
    size_t nvecs;
    vector<std::mutex> &locks;

    void dump() const
      {
      if (bu0<-nsafe) return; // nothing written into buffer yet

      int idxu = (bu0+nu)%nu;
      int idxv0 = (bv0+nv)%nv;
      for (int iu=0; iu<su; ++iu)
        {
        int idxv = idxv0;
        {
        std::lock_guard<std::mutex> lock(locks[idxu]);
        for (int iv=0; iv<sv; ++iv)
          {
          grid_w[idxu*nv + idxv] += wbuf[iu*sv + iv];
          if (++idxv>=nv) idxv=0;
          }
        }
        if (++idxu>=nu) idxu=0;
        }
      }

    void load()
      {
      int idxu = (bu0+nu)%nu;
      int idxv0 = (bv0+nv)%nv;
      for (int iu=0; iu<su; ++iu)
        {
        int idxv = idxv0;
        for (int iv=0; iv<sv; ++iv)
          {
          rbuf[iu*sv + iv] = grid_r[idxu*nv + idxv];
          if (++idxv>=nv) idxv=0;
          }
        if (++idxu>=nu) idxu=0;
        }
      }

  public:
    const T2 *p0r;
    T2 *p0w;
    T kernel[64] ALIGNED(64);
    static constexpr size_t vlen=native_simd<T>::size();

    Helper(const GridderConfig &gconf_, const T2 *grid_r_, T2 *grid_w_,
      vector<std::mutex> &locks_, double w0_=-1, double dw_=-1)
      : gconf(gconf_), nu(gconf.Nu()), nv(gconf.Nv()), nsafe(gconf.Nsafe()),
        supp(gconf.Supp()), beta(T(gconf.Beta())), grid_r(grid_r_),
        grid_w(grid_w_), su(2*nsafe+(1<<logsquare)), sv(2*nsafe+(1<<logsquare)),
        bu0(-1000000), bv0(-1000000),
        rbuf(su*sv*(grid_r!=nullptr),T(0)),
        wbuf(su*sv*(grid_w!=nullptr),T(0)),
        do_w_gridding(dw_>0),
        w0(w0_),
        xdw(T(1)/dw_),
        nexp(2*supp + do_w_gridding),
        nvecs(vlen*((nexp+vlen-1)/vlen)),
        locks(locks_)
      {}
    ~Helper() { if (grid_w) dump(); }

    int lineJump() const { return sv; }
    T Wfac() const { return kernel[2*supp]; }
    void prep(const UVW &in)
      {
      double u, v;
      gconf.getpix(in.u, in.v, u, v, iu0, iv0);
      double xsupp=2./supp;
      double x0 = xsupp*(iu0-u);
      double y0 = xsupp*(iv0-v);
      for (int i=0; i<supp; ++i)
        {
        kernel[i  ] = T(x0+i*xsupp);
        kernel[i+supp] = T(y0+i*xsupp);
        }
      if (do_w_gridding)
        kernel[2*supp] = min(T(1), T(xdw*xsupp*abs(w0-in.w)));
      for (size_t i=nexp; i<nvecs; ++i)
        kernel[i]=0;
      for (size_t i=0; i<nvecs; ++i)
Martin Reinecke's avatar
Martin Reinecke committed
676
677
678
679
680
681
        {
        kernel[i] = T(1) - kernel[i]*kernel[i];
        kernel[i] = (kernel[i]<0) ? T(-200.) : beta*(sqrt(kernel[i])-T(1));
        }
      for (size_t i=0; i<nvecs; ++i)
        kernel[i] = exp(kernel[i]);
Martin Reinecke's avatar
Martin Reinecke committed
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
      if ((iu0<bu0) || (iv0<bv0) || (iu0+supp>bu0+su) || (iv0+supp>bv0+sv))
        {
        if (grid_w) { dump(); fill(wbuf.begin(), wbuf.end(), T(0)); }
        bu0=((((iu0+nsafe)>>logsquare)<<logsquare))-nsafe;
        bv0=((((iv0+nsafe)>>logsquare)<<logsquare))-nsafe;
        if (grid_r) load();
        }
      p0r = grid_r ? rbuf.data() + sv*(iu0-bu0) + iv0-bv0 : nullptr;
      p0w = grid_w ? wbuf.data() + sv*(iu0-bu0) + iv0-bv0 : nullptr;
      }
  };

template<class T, class Serv> class SubServ
  {
  private:
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
697
698
    Serv &srv;
    mav<idx_t,1> subidx;
Martin Reinecke's avatar
Martin Reinecke committed
699
700

  public:
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
701
    SubServ(Serv &orig, const mav<idx_t,1> &subidx_)
Martin Reinecke's avatar
Martin Reinecke committed
702
703
704
705
      : srv(orig), subidx(subidx_){}
    size_t Nvis() const { return subidx.size(); }
    const Baselines &getBaselines() const { return srv.getBaselines(); }
    UVW getCoord(size_t i) const
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
706
      { return srv.getCoord(subidx(i)); }
Martin Reinecke's avatar
Martin Reinecke committed
707
    complex<T> getVis(size_t i) const
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
708
709
710
711
712
713
      { return srv.getVis(subidx(i)); }
    idx_t getIdx(size_t i) const { return srv.getIdx(subidx(i)); }
    void setVis (size_t i, const complex<T> &v)
      { srv.setVis(subidx(i), v); }
    void addVis (size_t i, const complex<T> &v)
      { srv.addVis(subidx(i), v); }
Martin Reinecke's avatar
Martin Reinecke committed
714
715
716
717
718
719
  };

template<class T, class T2> class MsServ
  {
  private:
    const Baselines &baselines;
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
720
    mav<idx_t,1> idx;
Martin Reinecke's avatar
Martin Reinecke committed
721
    T2 ms;
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
722
    mav<T,2> wgt;
Martin Reinecke's avatar
Martin Reinecke committed
723
724
725
726
727
728
729
    size_t nvis;
    bool have_wgt;

  public:
    using Tsub = SubServ<T, MsServ>;

    MsServ(const Baselines &baselines_,
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
730
    const mav<idx_t,1> &idx_, T2 ms_, const mav<T,2> &wgt_)
Martin Reinecke's avatar
Martin Reinecke committed
731
732
733
734
735
736
      : baselines(baselines_), idx(idx_), ms(ms_), wgt(wgt_),
        nvis(idx.shape(0)), have_wgt(wgt.size()!=0)
      {
      checkShape(ms.shape(), {baselines.Nrows(), baselines.Nchannels()});
      if (have_wgt) checkShape(wgt.shape(), ms.shape());
      }
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
737
    Tsub getSubserv(const mav<idx_t,1> &subidx)
Martin Reinecke's avatar
Martin Reinecke committed
738
739
740
741
742
743
744
745
746
747
748
      { return Tsub(*this, subidx); }
    size_t Nvis() const { return nvis; }
    const Baselines &getBaselines() const { return baselines; }
    UVW getCoord(size_t i) const
      { return baselines.effectiveCoord(idx(i)); }
    complex<T> getVis(size_t i) const
      {
      auto rc = baselines.getRowChan(idx(i));
      return have_wgt ? ms(rc.row, rc.chan)*wgt(rc.row, rc.chan)
                      : ms(rc.row, rc.chan);
      }
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
749
750
    idx_t getIdx(size_t i) const { return idx(i); }
    void setVis (size_t i, const complex<T> &v)
Martin Reinecke's avatar
Martin Reinecke committed
751
752
      {
      auto rc = baselines.getRowChan(idx(i));
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
753
      ms.w()(rc.row, rc.chan) = have_wgt ? v*wgt(rc.row, rc.chan) : v;
Martin Reinecke's avatar
Martin Reinecke committed
754
      }
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
755
    void addVis (size_t i, const complex<T> &v)
Martin Reinecke's avatar
Martin Reinecke committed
756
757
      {
      auto rc = baselines.getRowChan(idx(i));
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
758
      ms.v(rc.row, rc.chan) += have_wgt ? v*wgt(rc.row, rc.chan) : v;
Martin Reinecke's avatar
Martin Reinecke committed
759
760
761
762
      }
  };
template<class T, class T2> MsServ<T, T2> makeMsServ
  (const Baselines &baselines,
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
763
   const mav<idx_t,1> &idx, T2 &ms, const mav<T,2> &wgt)
Martin Reinecke's avatar
Martin Reinecke committed
764
765
766
  { return MsServ<T, T2>(baselines, idx, ms, wgt); }

template<typename T, typename Serv> void x2grid_c
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
767
  (const GridderConfig &gconf, Serv &srv, mav<complex<T>,2> &grid,
Martin Reinecke's avatar
Martin Reinecke committed
768
769
770
771
772
773
774
775
776
777
778
779
  double w0=-1, double dw=-1)
  {
  checkShape(grid.shape(), {gconf.Nu(), gconf.Nv()});
  MR_assert(grid.contiguous(), "grid is not contiguous");
  size_t supp = gconf.Supp();
  size_t nthreads = gconf.Nthreads();
  bool do_w_gridding = dw>0;
  vector<std::mutex> locks(gconf.Nu());

  size_t np = srv.Nvis();
  execGuided(np, nthreads, 100, 0.2, [&](Scheduler &sched)
    {
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
780
    Helper<T> hlp(gconf, nullptr, grid.vdata(), locks, w0, dw);
Martin Reinecke's avatar
Martin Reinecke committed
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
    int jump = hlp.lineJump();
    const T * MRUTIL_RESTRICT ku = hlp.kernel;
    const T * MRUTIL_RESTRICT kv = hlp.kernel+supp;

    while (auto rng=sched.getNext()) for(auto ipart=rng.lo; ipart<rng.hi; ++ipart)
      {
      UVW coord = srv.getCoord(ipart);
      auto flip = coord.FixW();
      hlp.prep(coord);
      auto * MRUTIL_RESTRICT ptr = hlp.p0w;
      auto v(srv.getVis(ipart));
      if (do_w_gridding) v*=hlp.Wfac();
      if (flip) v=conj(v);
      for (size_t cu=0; cu<supp; ++cu)
        {
        complex<T> tmp(v*ku[cu]);
        size_t cv=0;
        for (; cv+3<supp; cv+=4)
          {
          ptr[cv  ] += tmp*kv[cv  ];
          ptr[cv+1] += tmp*kv[cv+1];
          ptr[cv+2] += tmp*kv[cv+2];
          ptr[cv+3] += tmp*kv[cv+3];
          }
        for (; cv<supp; ++cv)
          ptr[cv] += tmp*kv[cv];
        ptr+=jump;
        }
      }
    });
  }

template<typename T, typename Serv> void grid2x_c
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
814
815
  (const GridderConfig &gconf, const mav<complex<T>,2> &grid,
  Serv &srv, double w0=-1, double dw=-1)
Martin Reinecke's avatar
Martin Reinecke committed
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
  {
  checkShape(grid.shape(), {gconf.Nu(), gconf.Nv()});
  MR_assert(grid.contiguous(), "grid is not contiguous");
  size_t supp = gconf.Supp();
  size_t nthreads = gconf.Nthreads();
  bool do_w_gridding = dw>0;
  vector<std::mutex> locks(gconf.Nu());

  // Loop over sampling points
  size_t np = srv.Nvis();
  execGuided(np, nthreads, 1000, 0.5, [&](Scheduler &sched)
    {
    Helper<T> hlp(gconf, grid.data(), nullptr, locks, w0, dw);
    int jump = hlp.lineJump();
    const T * MRUTIL_RESTRICT ku = hlp.kernel;
    const T * MRUTIL_RESTRICT kv = hlp.kernel+supp;

    while (auto rng=sched.getNext()) for(auto ipart=rng.lo; ipart<rng.hi; ++ipart)
      {
      UVW coord = srv.getCoord(ipart);
      auto flip = coord.FixW();
      hlp.prep(coord);
      complex<T> r = 0;
      const auto * MRUTIL_RESTRICT ptr = hlp.p0r;
      for (size_t cu=0; cu<supp; ++cu)
        {
        complex<T> tmp(0);
        size_t cv=0;
        for (; cv+3<supp; cv+=4)
          tmp += ptr[cv  ]*kv[cv  ]
               + ptr[cv+1]*kv[cv+1]
               + ptr[cv+2]*kv[cv+2]
               + ptr[cv+3]*kv[cv+3];
        for (; cv<supp; ++cv)
          tmp += ptr[cv] * kv[cv];
        r += tmp*ku[cu];
        ptr += jump;
        }
      if (flip) r=conj(r);
      if (do_w_gridding) r*=hlp.Wfac();
      srv.addVis(ipart, r);
      }
    });
  }

template<typename T> void apply_global_corrections(const GridderConfig &gconf,
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
862
  mav<T,2> &dirty, const ES_Kernel &kernel, double dw, bool divide_by_n)
Martin Reinecke's avatar
Martin Reinecke committed
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
  {
  auto nx_dirty=gconf.Nxdirty();
  auto ny_dirty=gconf.Nydirty();
  size_t nthreads = gconf.Nthreads();
  auto psx=gconf.Pixsize_x();
  auto psy=gconf.Pixsize_y();
  double x0 = -0.5*nx_dirty*psx,
         y0 = -0.5*ny_dirty*psy;
  auto cfu = correction_factors(gconf.Nu(), gconf.Ofactor(),
                                nx_dirty/2+1, gconf.Supp(), nthreads);
  auto cfv = correction_factors(gconf.Nv(), gconf.Ofactor(),
                                ny_dirty/2+1, gconf.Supp(), nthreads);
  execStatic(nx_dirty/2+1, nthreads, 0, [&](Scheduler &sched)
    {
    while (auto rng=sched.getNext()) for(auto i=rng.lo; i<rng.hi; ++i)
      {
      auto fx = T(x0+i*psx);
      fx *= fx;
      for (size_t j=0; j<=ny_dirty/2; ++j)
        {
        auto fy = T(y0+j*psy);
        fy*=fy;
        T fct = 0;
        auto tmp = 1-fx-fy;
        if (tmp>=0)
          {
          auto nm1 = (-fx-fy)/(sqrt(tmp)+1); // accurate form of sqrt(1-x-y)-1
          fct = T(kernel.corfac(nm1*dw));
          if (divide_by_n)
            fct /= nm1+1;
          }
        else // beyond the horizon, don't really know what to do here
          {
          if (divide_by_n)
            fct=0;
          else
            {
            auto nm1 = sqrt(-tmp)-1;
            fct = T(kernel.corfac(nm1*dw));
            }
          }
        fct *= T(cfu[nx_dirty/2-i]*cfv[ny_dirty/2-j]);
        size_t i2 = nx_dirty-i, j2 = ny_dirty-j;
Martin Reinecke's avatar
Martin Reinecke committed
906
        dirty.v(i,j)*=fct;
Martin Reinecke's avatar
Martin Reinecke committed
907
908
        if ((i>0)&&(i<i2))
          {
Martin Reinecke's avatar
Martin Reinecke committed
909
          dirty.v(i2,j)*=fct;
Martin Reinecke's avatar
Martin Reinecke committed
910
          if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
911
            dirty.v(i2,j2)*=fct;
Martin Reinecke's avatar
Martin Reinecke committed
912
913
          }
        if ((j>0)&&(j<j2))
Martin Reinecke's avatar
Martin Reinecke committed
914
          dirty.v(i,j2)*=fct;
Martin Reinecke's avatar
Martin Reinecke committed
915
916
917
918
919
920
921
922
        }
      }
    });
  }

template<typename Serv> class WgridHelper
  {
  private:
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
923
    Serv &srv;
Martin Reinecke's avatar
Martin Reinecke committed
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
    double wmin, dw;
    size_t nplanes, supp;
    vector<vector<idx_t>> minplane;
    size_t verbosity;

    int curplane;
    vector<idx_t> subidx;

    static void wminmax(const Serv &srv, double &wmin, double &wmax)
      {
      size_t nvis = srv.Nvis();

      wmin= 1e38;
      wmax=-1e38;
      // FIXME maybe this can be done more intelligently
      for (size_t ipart=0; ipart<nvis; ++ipart)
        {
        auto wval = abs(srv.getCoord(ipart).w);
        wmin = min(wmin,wval);
        wmax = max(wmax,wval);
        }
      }

    template<typename T> static void update_idx(vector<T> &v, const vector<T> &add,
      const vector<T> &del)
      {
      MR_assert(v.size()>=del.size(), "must not happen");
      vector<T> res;
      res.reserve((v.size()+add.size())-del.size());
      auto iin=v.begin(), ein=v.end();
      auto iadd=add.begin(), eadd=add.end();
      auto irem=del.begin(), erem=del.end();

      while(iin!=ein)
        {
        if ((irem!=erem) && (*iin==*irem))
          {  ++irem; ++iin; } // skip removed entry
        else if ((iadd!=eadd) && (*iadd<*iin))
           res.push_back(*(iadd++)); // add new entry
        else
          res.push_back(*(iin++));
        }
      MR_assert(irem==erem, "must not happen");
      while(iadd!=eadd)
        res.push_back(*(iadd++));
      MR_assert(res.size()==(v.size()+add.size())-del.size(), "must not happen");
      v.swap(res);
      }

  public:
Martin Reinecke's avatar
stage 2    
Martin Reinecke committed
974
    WgridHelper(const GridderConfig &gconf, Serv &srv_, size_t verbosity_)
Martin Reinecke's avatar
Martin Reinecke committed
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
      : srv(srv_), verbosity(verbosity_), curplane(-1)
      {
      size_t nvis = srv.Nvis();
      size_t nthreads = gconf.Nthreads();
      double wmax;

      wminmax(srv, wmin, wmax);
      if (verbosity>0) cout << "Using " << nthreads << " thread"
                            << ((nthreads!=1) ? "s" : "") << endl;
      if (verbosity>0) cout << "W range: " << wmin << " to " << wmax << endl;

      double x0 = -0.5*gconf.Nxdirty()*gconf.Pixsize_x(),
             y0 = -0.5*gconf.Nydirty()*gconf.Pixsize_y();
      double nmin = sqrt(max(1.-x0*x0-y0*y0,0.))-1.;
      if (x0*x0+y0*y0>1.)
        nmin = -sqrt(abs(1.-x0*x0-y0*y0))-1.;
      dw = 0.25/abs(nmin);
      nplanes = size_t((wmax-wmin)/dw+2);
      dw = (1.+1e-13)*(wmax-wmin)/(nplanes-1);

      supp = gconf.Supp();
      wmin -= (0.5*supp-1)*dw;
      wmax += (0.5*supp-1)*dw;
      nplanes += supp-2;
      if (verbosity>0) cout << "Kernel support: " << supp << endl;
      if (verbosity>0) cout << "nplanes: " << nplanes << endl;
For faster browsing, not all history is shown. View entire blame