1# http://pyrocko.org - GPLv3 

2# 

3# The Pyrocko Developers, 21st Century 

4# ---|P------/S----------~Lg---------- 

5 

6import logging 

7import numpy as num 

8import matplotlib.pyplot as plt 

9 

10from matplotlib.cm import ScalarMappable 

11from matplotlib.ticker import FuncFormatter 

12 

13from pyrocko.plot import beachball 

14from pyrocko.gf.meta import Timing 

15from pyrocko.gf import LocalEngine, Target, RectangularSource, map_anchor 

16from pyrocko.util import num_full_like 

17 

18 

19km = 1e3 

20r2d = 180. / num.pi 

21d2r = num.pi / 180. 

22 

23logger = logging.getLogger(__name__) 

24 

25 

26QUANTITY_LABEL = { 

27 'displacement': 'Displacement [m]', 

28 'velocity': 'Velocity [m/s]', 

29 'acceleration': 'Acceleration [m/s²]' 

30} 

31 

32 

33def get_azimuthal_targets( 

34 store_id, source, radius, 

35 azi_begin=0., azi_end=360., dazi=1., 

36 depth=0.0, 

37 interpolation='multilinear', 

38 components='RTZ', quantity='displacement'): 

39 

40 assert dazi > 0. 

41 assert azi_begin < azi_end 

42 

43 nstations = int((azi_end - azi_begin) // dazi) 

44 assert nstations > 0 

45 

46 azimuths = num.linspace(azi_begin, azi_end, nstations) 

47 

48 coords = num.zeros((2, nstations)) 

49 coords[0, :] = num.cos(azimuths*d2r) 

50 coords[1, :] = num.sin(azimuths*d2r) 

51 coords *= radius 

52 

53 dips = {'R': 0., 'T': 0., 'Z': -90.} 

54 for comp in components: 

55 assert comp in dips.keys() 

56 

57 target_kwargs = dict( 

58 quantity=quantity, 

59 interpolation=interpolation, 

60 store_id=store_id) 

61 

62 targets = [ 

63 Target( 

64 lat=source.lat, 

65 lon=source.lon, 

66 north_shift=coords[0, iazi] + source.north_shift, 

67 east_shift=coords[1, iazi] + source.east_shift, 

68 depth=depth, 

69 azimuth={ 

70 'R': azi, 

71 'T': azi+90., 

72 'Z': 0. 

73 }[channel], 

74 dip=dips[channel], 

75 codes=('', 'S%01d' % iazi, '', channel), 

76 **target_kwargs) 

77 for iazi, azi in enumerate(azimuths) 

78 for channel in components] 

79 

80 for target, azi in zip(targets, azimuths): 

81 target.azimuth = azi 

82 target.dazi = dazi 

83 

84 return targets, azimuths 

85 

86 

87def get_seismogram_array( 

88 response, fmin=None, fmax=None, 

89 component='R', envelope=False): 

90 resp = response 

91 assert len(resp.request.sources) == 1, 'more than one source in response' 

92 

93 tmin = None 

94 tmax = None 

95 traces = [] 

96 

97 for _, target, tr in response.iter_results(): 

98 if target.codes[-1] != component: 

99 continue 

100 assert hasattr(target, 'azimuth') 

101 assert target.dazi 

102 

103 if fmin is not None: 

104 tr.highpass(4, fmin, demean=False) 

105 

106 if fmax is not None: 

107 tr.lowpass(4, fmax, demean=False) 

108 

109 tmin = min(tmin, tr.tmin) if tmin else tr.tmin 

110 tmax = max(tmax, tr.tmax) if tmax else tr.tmax 

111 traces.append(tr) 

112 

113 for tr in traces: 

114 tr.extend(tmin, tmax, fillmethod='repeat') 

115 if envelope: 

116 tr.envelope() 

117 

118 data = num.array([tr.get_ydata() for tr in traces]) 

119 nsamples = data.shape[1] 

120 return data, num.linspace(tmin, tmax, nsamples) 

121 

122 

123def hillshade(array, azimuth, angle_altitude): 

124 azimuth = 360.0 - azimuth 

125 azi = azimuth * r2d 

126 alt = angle_altitude * r2d 

127 

128 x, y = num.gradient(array) 

129 slope = num.pi/2. - num.arctan(num.sqrt(x*x + y*y)) 

130 aspect = num.arctan2(-x, y) 

131 

132 shaded = num.sin(alt)*num.sin(slope) \ 

133 + num.cos(alt)*num.cos(slope)*num.cos((azi - num.pi/2.) - aspect) 

134 

135 return (shaded + 1.)/2. 

136 

137 

138def hillshade_seismogram_array( 

139 seismogram_array, rgba_map, 

140 shad_lim=(.4, .98), contrast=1., blend_mode='multiply'): 

141 assert blend_mode in ('multiply', 'screen'), 'unknown blend mode' 

142 assert shad_lim[0] < shad_lim[1], 'bad shading limits' 

143 from scipy.ndimage import convolve as im_conv 

144 # Light source from somewhere above - psychologically the best choice 

145 # from upper left 

146 ramp = num.array([[1., 0.], [0., -1.]]) * contrast 

147 

148 # convolution of two 2D arrays 

149 shad = im_conv(seismogram_array, ramp.T).ravel() 

150 shad *= -1. 

151 

152 # if there are strong artifical edges in the data, shades get 

153 # dominated by them. Cutting off the largest and smallest 2% of 

154 # # shades helps 

155 percentile2 = num.percentile(shad, 2.0) 

156 percentile98 = num.percentile(shad, 98.0) 

157 

158 shad[shad > percentile98] = percentile98 

159 shad[shad < percentile2] = percentile2 

160 

161 # # normalize shading 

162 shad -= num.nanmin(shad) 

163 shad /= num.nanmax(shad) 

164 

165 # # reduce range to balance gray color 

166 shad *= shad_lim[1] - shad_lim[0] 

167 shad += shad_lim[0] 

168 

169 if blend_mode == 'screen': 

170 rgba_map[:, :3] = 1. - ((1. - rgba_map[:, :3])*(shad[:, num.newaxis])) 

171 elif blend_mode == 'multiply': 

172 rgba_map[:, :3] *= shad[:, num.newaxis] 

173 

174 return rgba_map 

175 

176 

177def plot_directivity( 

178 engine, source, store_id, 

179 distance=300*km, azi_begin=0., azi_end=360., dazi=1., 

180 phases={'P': 'first{stored:any_P}-10%', 

181 'S': 'last{stored:any_S}+50'}, 

182 interpolation='multilinear', 

183 target_depth=0.0, 

184 quantity='displacement', envelope=False, 

185 component='R', fmin=0.01, fmax=0.1, 

186 hillshade=True, cmap=None, 

187 plot_mt='full', show_phases=True, show_description=True, 

188 reverse_time=False, show_nucleations=True, axes=None, nthreads=0): 

189 ''' 

190 Plot the directivity and radiation characteristics of source models. 

191 

192 Synthetic seismic traces (R, T or Z) are forward-modelled at a defined 

193 radius, covering the full or partial azimuthal range and projected on a 

194 polar plot. Difference in the amplitude are enhanced by hillshading 

195 the data. 

196 

197 :param engine: Forward modelling engine 

198 :type engine: :py:class:`~pyrocko.gf.seismosizer.Engine` 

199 :param source: Parametrized source model 

200 :type source: :py:class:`~pyrocko.gf.seismosizer.Source` 

201 :param store_id: Store ID used for forward modelling 

202 :type store_id: str 

203 :param distance: Distance in [m] 

204 :type distance: float 

205 :param azi_begin: Begin azimuth in [deg] 

206 :type azi_begin: float 

207 :param azi_end: End azimuth in [deg] 

208 :type azi_end: float 

209 :param dazi: Delta azimuth, bin size [deg] 

210 :type dazi: float 

211 :param phases: Phases to define start and end of time window 

212 :type phases: :py:class:`dict` with :py:class:`str` keys and 

213 :py:class:`~pyrocko.gf.meta.Timing` values 

214 :param quantity: Seismogram quantity, default ``displacement`` 

215 :type quantity: str 

216 :param envelope: Plot envelope instead of seismic trace 

217 :type envelope: bool 

218 :param component: Forward modelled component, default ``R``. Choose from 

219 `RTZ` 

220 :type component: str 

221 :param fmin: Bandpass lower frequency [Hz], default ``0.01`` 

222 :type fmin: float 

223 :param fmax: Bandpass upper frequency [Hz], default ``0.1`` 

224 :type fmax: float 

225 :param hillshade: Enable hillshading, default ``True`` 

226 :type hillshade: bool 

227 :param cmap: Matplotlib colormap to use, default ``seismic``. 

228 When ``envelope`` is ``True`` the default colormap will be ``Reds``. 

229 :type cmap: str 

230 :param plot_mt: Plot a centered moment tensor, default ``full``. 

231 Choose from ``full, deviatoric, dc or False`` 

232 :type plot_mt: str, bool 

233 :param show_phases: Show annotations, default ``True`` 

234 :type show_phases: bool 

235 :param show_description: Show description, default ``True`` 

236 :type show_description: bool 

237 :param reverse_time: Reverse time axis. First phases arrive at the center, 

238 default ``False`` 

239 :type reverse_time: bool 

240 :param show_nucleations: Show nucleation piercing points on the moment 

241 tensor, default ``True`` 

242 :type show_nucleations: bool 

243 :param axes: Give axes to plot into 

244 :type axes: :py:class:`matplotlib.axes.Axes` 

245 :param nthreads: Number of threads used for forward modelling, 

246 default ``0`` - all available cores 

247 :type nthreads: int 

248 ''' 

249 

250 if axes is None: 

251 fig = plt.figure() 

252 ax = fig.add_subplot(111, polar=True) 

253 else: 

254 fig = axes.figure 

255 ax = axes 

256 

257 if envelope and cmap is None: 

258 cmap = 'Reds' 

259 elif cmap is None: 

260 cmap = 'seismic' 

261 

262 targets, azimuths = get_azimuthal_targets( 

263 store_id, source, distance, azi_begin, azi_end, dazi, 

264 depth=target_depth, 

265 interpolation=interpolation, 

266 components='R', quantity=quantity) 

267 ref_target = targets[0] 

268 store = engine.get_store(store_id) 

269 mt = source.pyrocko_moment_tensor(store=store, target=ref_target) 

270 

271 resp = engine.process(source, targets, nthreads=nthreads) 

272 data, times = get_seismogram_array( 

273 resp, fmin, fmax, 

274 component=component, envelope=envelope) 

275 

276 nucl_depth = source.depth 

277 nucl_distance = distance 

278 

279 if hasattr(source, 'nucleation_x') and hasattr(source, 'nucleation_y'): 

280 try: 

281 iter(source.nucleation_x) 

282 nx = float(source.nucleation_x[0]) 

283 ny = float(source.nucleation_y[0]) 

284 

285 except TypeError: 

286 nx = source.nucleation_x 

287 ny = source.nucleation_y 

288 

289 nucl_distance += nx * source.length/2. 

290 nucl_depth += ny*num.sin(source.dip*d2r) * source.width/2. 

291 

292 if hasattr(source, 'anchor'): 

293 anch_x, anch_y = map_anchor[source.anchor] 

294 nucl_distance -= anch_x * source.length/2. 

295 nucl_depth -= anch_y*num.sin(source.dip*d2r) * source.width/2. 

296 

297 timings = [Timing(p) for p in phases.values()] 

298 phase_times = [store.t(t, source, ref_target) for t in timings] 

299 

300 tbegin = min(phase_times) 

301 tend = max(phase_times) 

302 tsel = num.logical_and(times >= tbegin, times <= tend) 

303 

304 data = data[:, tsel].T 

305 times = times[tsel] 

306 duration = times[-1] - times[0] 

307 

308 vmax = num.abs(data).max() 

309 cmw = ScalarMappable(cmap=cmap) 

310 cmw.set_array(data) 

311 cmw.set_clim(-vmax, vmax) 

312 

313 if envelope: 

314 cmw.set_clim(0., vmax) 

315 

316 ax.set_theta_zero_location('N') 

317 ax.set_theta_direction(-1) 

318 

319 strike_label = mt.strike1 

320 if hasattr(source, 'strike'): 

321 strike_label = source.strike 

322 

323 try: 

324 ax.set_rlabel_position(strike_label % 180. - 180.) 

325 except AttributeError: 

326 logger.warning('Old matplotlib version: cannot set label positions') 

327 

328 def r_fmt(v, p): 

329 if v < tbegin or v > tend: 

330 return '' 

331 return '%g s' % v 

332 

333 ax.yaxis.set_major_formatter(FuncFormatter(r_fmt)) 

334 if reverse_time: 

335 ax.set_rlim(times[0] - .3*duration, times[-1]) 

336 else: 

337 ax.set_rlim(times[-1] + .3*duration, times[0]) 

338 

339 ax.grid(zorder=20) 

340 

341 if isinstance(plot_mt, str): 

342 mt_size = .15 

343 beachball.plot_beachball_mpl( 

344 mt, ax, 

345 beachball_type=plot_mt, size=mt_size, 

346 size_units='axes', color_t=(0.7, 0.4, 0.4), 

347 position=(.5, .5), linewidth=1.) 

348 

349 if hasattr(source, 'nucleation_x') and hasattr(source, 'nucleation_y')\ 

350 and show_nucleations: 

351 try: 

352 iter(source.nucleation_x) 

353 nucleation_x = source.nucleation_x 

354 nucleation_y = source.nucleation_y 

355 except TypeError: 

356 nucleation_x = [source.nucleation_x] 

357 nucleation_y = [source.nucleation_y] 

358 

359 for nx, ny in zip(nucleation_x, nucleation_y): 

360 angle = float(num.arctan2(ny, nx)) 

361 rtp = num.array([[1., angle, (90.-source.strike)*d2r]]) 

362 points = beachball.numpy_rtp2xyz(rtp) 

363 x, y = beachball.project(points, projection='lambert').T 

364 norm = num.sqrt(x**2 + y**2) 

365 x = x / norm * mt_size/2. 

366 y = y / norm * mt_size/2. 

367 ax.plot(x+.5, y+.5, 'x', ms=6, mew=2, mec='darkred', mfc='red', 

368 transform=ax.transAxes, zorder=10) 

369 

370 mesh = ax.pcolormesh( 

371 azimuths * d2r, times, data, 

372 cmap=cmw.cmap, norm=cmw.norm, shading='gouraud', zorder=0) 

373 

374 if hillshade: 

375 mesh.update_scalarmappable() 

376 color = mesh.get_facecolor() 

377 color = hillshade_seismogram_array( 

378 data, color, shad_lim=(.85, 1.), blend_mode='multiply') 

379 mesh.set_facecolor(color) 

380 

381 if show_phases: 

382 label_theta = 270. 

383 theta = num.linspace(0, 2*num.pi, 360) 

384 

385 for label, phase_str in phases.items(): 

386 phase = Timing(phase_str) 

387 

388 phase.offset = 0. 

389 phase.offset_is_slowness = False 

390 phase.offset_is_percent = False 

391 

392 time = store.t(phase, source, ref_target) 

393 times = num_full_like(theta, time) 

394 

395 ax.plot(theta, times, color='k', alpha=.3, lw=1., ls='--') 

396 

397 ax.text( 

398 label_theta*d2r, time, label, 

399 ha='left', color='k', fontsize='small') 

400 label_theta += 30. 

401 

402 if show_description: 

403 description = ( 

404 'Component {component:s}\n' 

405 'Distance {distance:g} km').format( 

406 component=component, distance=distance / km) 

407 

408 if fmin and fmax: 

409 description += '\nBandpass {fmin:g} - {fmax:g} Hz'.format( 

410 fmin=fmin, fmax=fmax) 

411 elif fmin: 

412 description += '\nHighpass {fmin:g} Hz'.format(fmin=fmin) 

413 elif fmax: 

414 description += '\nLowpass {fmax:g} Hz'.format(fmax=fmax) 

415 ax.text( 

416 -.05, -.05, description, 

417 fontsize='small', 

418 ha='left', va='bottom', transform=ax.transAxes) 

419 

420 cbar_label = QUANTITY_LABEL[quantity] 

421 if envelope: 

422 cbar_label = 'Envelope ' + cbar_label 

423 

424 cb = fig.colorbar( 

425 cmw, ax=ax, 

426 orientation='vertical', shrink=.8, pad=0.11) 

427 

428 cb.set_label(cbar_label) 

429 

430 if axes is None: 

431 plt.show() 

432 return resp 

433 

434 

435__all__ = ['plot_directivity'] 

436 

437 

438if __name__ == '__main__': 

439 engine = LocalEngine(store_superdirs=['.'], use_config=True) 

440 

441 rect_source = RectangularSource( 

442 depth=2.6*km, 

443 strike=240., 

444 dip=76.6, 

445 rake=-.4, 

446 anchor='top', 

447 

448 nucleation_x=-.57, 

449 nucleation_y=-.59, 

450 velocity=2070., 

451 

452 length=27*km, 

453 width=9.4*km, 

454 slip=1.4) 

455 

456 resp = plot_directivity( 

457 engine, rect_source, 'crust2_ib', 

458 dazi=5, component='R', quantity='displacement', envelope=True)