Commit 1d4deeb6 authored by Martin Reinecke's avatar Martin Reinecke

Merge branch 'better_beta' into 'master'

Better beta

See merge request !24
parents 7cac7cb7 bcfb7c6a
......@@ -375,7 +375,7 @@ class ES_Kernel
public:
ES_Kernel(size_t supp_, size_t nthreads)
: beta(2.3*supp_), p(int(1.5*supp_+2)), supp(supp_)
: beta(get_beta(supp_)*supp_), p(int(1.5*supp_+2)), supp(supp_)
{
legendre_prep(2*p,x,wgt,nthreads);
psi=x;
......@@ -392,16 +392,24 @@ class ES_Kernel
tmp += wgt[i]*psi[i]*cos(pi*supp*v*x[i]);
return 1./(supp*tmp);
}
static double get_beta(size_t supp)
{
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};
myassert(supp<opt_beta.size(), "bad support size");
return opt_beta[supp];
}
static size_t get_supp(double epsilon)
{
static const vector<double> maxmaperr { 1e8, 0.32, 0.021, 6.2e-4,
1.08e-5, 1.25e-7, 8.25e-10, 5.70e-12, 1.22e-13, 2.48e-15, 4.82e-17,
6.74e-19, 5.41e-21, 4.41e-23, 7.88e-25, 3.9e-26 };
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 };
double epssq = epsilon*epsilon;
for (size_t i=1; i<maxmaperr.size(); ++i)
if (epssq>maxmaperr[i]) return i;
myfail("requested epsilon too small - minimum is 2e-13");
myfail("requested epsilon too small - minimum is 1e-13");
}
};
......@@ -552,7 +560,7 @@ class GridderConfig
psx(pixsize_x), psy(pixsize_y),
supp(ES_Kernel::get_supp(epsilon)), nsafe((supp+1)/2),
nu(max(2*nsafe,2*nx_dirty)), nv(max(2*nsafe,2*ny_dirty)),
beta(2.3*supp),
beta(ES_Kernel::get_beta(supp)*supp),
cfu(nx_dirty), cfv(ny_dirty), nthreads(nthreads_),
ushift(supp*(-0.5)+1+nu), vshift(supp*(-0.5)+1+nv),
maxiu0((nu+nsafe)-supp), maxiv0((nv+nsafe)-supp)
......@@ -1214,16 +1222,14 @@ template<typename T> void apply_wcorr(const GridderConfig &gconf,
}
}
template<typename Serv> void wstack_common(
const GridderConfig &gconf, const Serv &srv, double &wmin,
double &dw, size_t &nplanes, vector<size_t> &nvis_plane,
vector<int> &minplane, size_t verbosity)
template<typename Serv> void wminmax(const GridderConfig &gconf,
const Serv &srv, double &wmin, double &wmax)
{
size_t nvis = srv.Nvis();
size_t nthreads = gconf.Nthreads();
wmin=1e38;
double wmax=-1e38;
wmin= 1e38;
wmax=-1e38;
// FIXME maybe this can be done more intelligently
#pragma omp parallel for num_threads(nthreads) reduction(min:wmin) reduction(max:wmax)
for (size_t ipart=0; ipart<nvis; ++ipart)
......@@ -1232,6 +1238,18 @@ template<typename Serv> void wstack_common(
wmin = min(wmin,wval);
wmax = max(wmax,wval);
}
}
template<typename Serv> void wstack_common(
const GridderConfig &gconf, const Serv &srv, double &wmin,
double &dw, size_t &nplanes, vector<size_t> &nvis_plane,
vector<int> &minplane, size_t verbosity)
{
size_t nvis = srv.Nvis();
size_t nthreads = gconf.Nthreads();
double wmax;
wminmax(gconf, srv, wmin, wmax);
if (verbosity>0) cout << "Using " << nthreads << " threads" << endl;
if (verbosity>0) cout << "W range: " << wmin << " to " << wmax << endl;
double x0 = -0.5*gconf.Nxdirty()*gconf.Pixsize_x(),
......
......@@ -15,7 +15,7 @@ def _init_gridder(nxdirty, nydirty, epsilon, nchan, nrow):
epsilon=epsilon,
pixsize_x=0.368*pixsize,
pixsize_y=pixsize)
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsize*f0/speedoflight)
baselines = ng.Baselines(coord=uvw, freq=freq)
......@@ -24,26 +24,6 @@ def _init_gridder(nxdirty, nydirty, epsilon, nchan, nrow):
return baselines, conf, idx
def _dft(uvw, vis, conf, apply_w):
shp = (conf.Nxdirty(), conf.Nydirty())
x, y = np.meshgrid(*[-ss/2 + np.arange(ss) for ss in shp],
indexing='ij')
x *= conf.Pixsize_x()
y *= conf.Pixsize_y()
dirty = np.zeros(shp, dtype=np.complex128)
if apply_w:
n = np.sqrt(1-x**2-y**2)
nm1 = n-1
for ii, vv in enumerate(vis):
phase = x*uvw[ii, 0] + y*uvw[ii, 1]
if apply_w:
phase -= uvw[ii, 2]*nm1
dirty += (vv*np.exp(2j*np.pi*phase)).real
if apply_w:
return dirty/n
return dirty
def _l2error(a, b):
return np.sqrt(np.sum(np.abs(a-b)**2)/np.maximum(np.sum(np.abs(a)**2),
np.sum(np.abs(b)**2)))
......@@ -90,7 +70,7 @@ def test_adjointness_ms2dirty(nxdirty, nydirty, nrow, nchan, epsilon, singleprec
np.random.seed(42)
pixsizex = np.pi/180/60/nxdirty*0.2398
pixsizey = np.pi/180/60/nxdirty
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsizey*f0/speedoflight)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
......@@ -125,7 +105,7 @@ def test_ms2dirty_against_wdft(nxdirty, nydirty, nrow, nchan, epsilon, singlepre
np.random.seed(40)
pixsizex = fov*np.pi/180/nxdirty
pixsizey = fov*np.pi/180/nydirty*1.1
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsizex*f0/speedoflight)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
......@@ -185,10 +165,9 @@ def test_hoisted_grid_allocation(nxdirty, nydirty, nrow, nchan, epsilon):
gconf = ng.GridderConfig(1024, 1024, 2e-13, 2.0, 2.0)
freq = np.linspace(.856e9, 2*.856e9, nchan)
f0 = freq[freq.shape[0]//2]
speedoflight = 3e8
pixsize = np.pi/180/60/nxdirty # assume 1 arcmin FOV
speedoflight = 3e8
speedoflight = 299792458.
uvw = (np.random.rand(nrow, 3)-0.5) / (pixsize*f0/speedoflight)
baselines = ng.Baselines(coord=uvw, freq=freq)
gconf = ng.GridderConfig(nxdirty=nxdirty, nydirty=nydirty,
......@@ -327,22 +306,6 @@ def test_no_correlation(nrow, nchan, epsilon, weight):
ng.get_correlations(bl, conf, idx, uu, vv, wgt)
@pmp('epsilon', [1e-2, 1e-4, 1e-7, 1e-10, 1e-11, 1e-12, 2e-13])
@pmp('nxdirty', [2, 12, 128])
@pmp('nydirty', [2, 4, 12, 128])
@pmp("nrow", (10, 100))
@pmp("nchan", (1, 10))
def test_against_dft(nxdirty, nydirty, epsilon, nchan, nrow):
np.random.seed(42)
bl, conf, idx = _init_gridder(nxdirty, nydirty, epsilon, nchan, nrow)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
vis = bl.ms2vis(ms, idx)
uvw = bl.effectiveuvw(idx)
res0 = conf.grid2dirty_c(ng.vis2grid_c(bl, conf, idx, vis)).real
res1 = _dft(uvw, vis, conf, False)
assert_(_l2error(res0, res1) < epsilon)
@pmp('nxdirty', [16, 64])
@pmp('nydirty', [64])
@pmp("nrow", (10, 100))
......@@ -357,7 +320,7 @@ def test_wstack_against_wdft(nxdirty, nydirty, nchan, nrow, fov):
epsilon=epsilon,
pixsize_x=pixsize,
pixsize_y=0.5*pixsize)
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsize*f0/speedoflight)
bl = ng.Baselines(coord=uvw, freq=freq)
......@@ -365,9 +328,9 @@ def test_wstack_against_wdft(nxdirty, nydirty, nchan, nrow, fov):
idx = ng.getIndices(bl, conf, flags)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
vis = bl.ms2vis(ms, idx)
uvw = bl.effectiveuvw(idx)
res0 = np.zeros((nxdirty, nydirty), dtype=np.float64)
mi, ma = np.min(np.abs(uvw[:, 2])), np.max(np.abs(uvw[:, 2]))
mi = np.min(np.abs(uvw[:, 2]))*freq[0]/speedoflight
ma = np.max(np.abs(uvw[:, 2]))*freq[-1]/speedoflight
nplanes = 10000
ws = mi + np.arange(nplanes)*(ma-mi)/(nplanes-1)
for ii in range(len(ws)-1):
......@@ -378,7 +341,8 @@ def test_wstack_against_wdft(nxdirty, nydirty, nchan, nrow, fov):
continue
dd = conf.grid2dirty_c(ng.vis2grid_c(bl, conf, iind, bl.ms2vis(ms, iind)))
res0 += conf.apply_wscreen(dd, 0.5*(ws[ii+1]+ws[ii]), adjoint=True).real
res1 = _dft(uvw, vis, conf, True)
res1 = explicit_gridder(uvw, freq, ms, None, nxdirty, nydirty, pixsize,
0.5*pixsize, True)
assert_(_l2error(res0, res1) < 1e-4) # Very inaccurate
......@@ -396,7 +360,7 @@ def test_wplane_against_wdft(nxdirty, nydirty, nchan, nrow, fov):
epsilon=epsilon,
pixsize_x=pixsize,
pixsize_y=0.2*pixsize)
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsize*f0/speedoflight)
uvw[:, 2] = uvw[0, 2] # use exactly one random w
......@@ -405,12 +369,12 @@ def test_wplane_against_wdft(nxdirty, nydirty, nchan, nrow, fov):
idx = ng.getIndices(bl, conf, flags)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
vis = bl.ms2vis(ms, idx)
uvw = bl.effectiveuvw(idx)
w = np.min(uvw[:, 2])
w = np.min(uvw[:, 2])*freq[0]/speedoflight
iind = ng.getIndices(bl, conf, flags)
dd = conf.grid2dirty_c(ng.vis2grid_c(bl, conf, iind, bl.ms2vis(ms, iind)))
res0 = conf.apply_wscreen(dd, w, adjoint=True).real
res1 = _dft(uvw, vis, conf, True)
res1 = explicit_gridder(uvw, freq, ms, None, nxdirty, nydirty, pixsize,
0.2*pixsize, True)
assert_(_l2error(res0, res1) < epsilon)
......@@ -428,7 +392,7 @@ def test_wgridder_against_wdft(nxdirty, nydirty, nchan, nrow, fov, epsilon):
epsilon=epsilon,
pixsize_x=pixsize,
pixsize_y=0.5*pixsize)
speedoflight, f0 = 3e8, 1e9
speedoflight, f0 = 299792458., 1e9
freq = f0 + np.arange(nchan)*(f0/nchan)
uvw = (np.random.rand(nrow, 3)-0.5)/(pixsize*f0/speedoflight)
bl = ng.Baselines(coord=uvw, freq=freq)
......@@ -436,9 +400,9 @@ def test_wgridder_against_wdft(nxdirty, nydirty, nchan, nrow, fov, epsilon):
idx = ng.getIndices(bl, conf, flags)
ms = np.random.rand(nrow, nchan)-0.5 + 1j*(np.random.rand(nrow, nchan)-0.5)
vis = bl.ms2vis(ms, idx)
uvw = bl.effectiveuvw(idx)
res0 = ng.vis2dirty(bl, conf, idx, vis, do_wstacking=True)
res1 = _dft(uvw, vis, conf, True)
res1 = explicit_gridder(uvw, freq, ms, None, nxdirty, nydirty, pixsize,
0.5*pixsize, True)
assert_(_l2error(res0, res1) < epsilon)
......@@ -473,4 +437,4 @@ def test_holo_from_correlations(nxdirty, nydirty, nchan, nrow, epsilon):
res0 += np.roll(d1[ii]*grid, du, axis=0)
res0 += d2*grid
res1 = ng.apply_holo(bl, conf, idx, grid)
assert_allclose(res0, res1, rtol=1e-13)
assert_allclose(res0, res1, rtol=1e-13, atol=1e-13)
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