Example on retrieving and plotting winds#
This is a simple example for how to retrieve and plot winds from 2 radars using PyDDA.
Author: Robert C. Jackson
import pydda
from matplotlib import pyplot as plt
berr_grid = pydda.io.read_grid(pydda.tests.EXAMPLE_RADAR0)
cpol_grid = pydda.io.read_grid(pydda.tests.EXAMPLE_RADAR1)
# Load sounding data and insert as an intialization
berr_grid = pydda.initialization.make_constant_wind_field(
berr_grid, (0.0, 0.0, 0.0), vel_field="corrected_velocity"
)
# Start the wind retrieval. This example only uses the mass continuity
# and data weighting constraints.
Grids, _ = pydda.retrieval.get_dd_wind_field(
[berr_grid, cpol_grid],
Co=1.0,
Cm=256.0,
Cx=0.0,
Cy=0.0,
Cz=0.0,
Cb=0.0,
frz=5000.0,
filter_window=5,
mask_outside_opt=True,
upper_bc=1,
wind_tol=0.5,
engine="scipy",
parallel=False,
)
# Plot a horizontal cross section
plt.figure(figsize=(9, 9))
pydda.vis.plot_horiz_xsection_barbs(
Grids,
background_field="reflectivity",
level=6,
w_vel_contours=[5, 10, 15],
barb_spacing_x_km=5.0,
barb_spacing_y_km=15.0,
vmin=0,
vmax=70,
)
plt.show()
# Plot a vertical X-Z cross section
plt.figure(figsize=(9, 9))
pydda.vis.plot_xz_xsection_barbs(
Grids,
background_field="reflectivity",
level=40,
w_vel_contours=[5, 10, 15],
barb_spacing_x_km=10.0,
barb_spacing_z_km=2.0,
vmin=0,
vmax=70,
)
plt.show()
# Plot a vertical Y-Z cross section
plt.figure(figsize=(9, 9))
pydda.vis.plot_yz_xsection_barbs(
Grids,
background_field="reflectivity",
level=40,
barb_spacing_y_km=10.0,
barb_spacing_z_km=2.0,
vmin=0,
vmax=70,
)
plt.show()
## You are using the Python ARM Radar Toolkit (Py-ART), an open source
## library for working with weather radar data. Py-ART is partly
## supported by the U.S. Department of Energy as part of the Atmospheric
## Radiation Measurement (ARM) Climate Research Facility, an Office of
## Science user facility.
##
## If you use this software to prepare a publication, please cite:
##
## JJ Helmus and SM Collis, JORS 2016, doi: 10.5334/jors.119
Welcome to PyDDA 2.4.1
If you are using PyDDA in your publications, please cite:
Jackson et al. (2020) Journal of Open Research Science
Detecting Jax...
Jax/JaxOpt are not installed on your system, unable to use Jax engine.
Detecting TensorFlow...
Unable to load both TensorFlow and tensorflow-probability. TensorFlow engine disabled.
No module named 'tensorflow'
False
Calculating weights for radars 0 and 1
Calculating weights for radars 1 and 0
Calculating weights for models...
Starting solver
rmsVR = 6.827303971100176
Total points: 81194
The max of w_init is 0.0
Total number of model points: 0
Nfeval | Jvel | Jmass | Jsmooth | Jbg | Jvort | Jmodel | Jpoint | Max w
0|83859.8222| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000
The gradient of the cost functions is 0.6631357968996351
Nfeval | Jvel | Jmass | Jsmooth | Jbg | Jvort | Jmodel | Jpoint | Max w
10| 1.8782| 41.0864| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 11.3085
Max change in w: 10.561
The gradient of the cost functions is 0.13750649771707754
Nfeval | Jvel | Jmass | Jsmooth | Jbg | Jvort | Jmodel | Jpoint | Max w
20| 0.3524| 18.6065| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 11.8823
Max change in w: 6.008
The gradient of the cost functions is 0.09828068193834624
Nfeval | Jvel | Jmass | Jsmooth | Jbg | Jvort | Jmodel | Jpoint | Max w
30| 0.1953| 10.8039| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 12.4880
Max change in w: 4.003
The gradient of the cost functions is 0.09730430370872419
Nfeval | Jvel | Jmass | Jsmooth | Jbg | Jvort | Jmodel | Jpoint | Max w
40| 0.1245| 7.0774| 0.0000| 0.0000| 0.0000| 0.0000| 0.0000| 16.4854
Max change in w: 5.381
---------------------------------------------------------------------------
KeyboardInterrupt Traceback (most recent call last)
Cell In[1], line 14
10 )
11
12 # Start the wind retrieval. This example only uses the mass continuity
13 # and data weighting constraints.
---> 14 Grids, _ = pydda.retrieval.get_dd_wind_field(
15 [berr_grid, cpol_grid],
16 Co=1.0,
17 Cm=256.0,
File ~/work/PyDDA/PyDDA/pydda/retrieval/wind_retrieve.py:1502, in get_dd_wind_field(Grids, u_init, v_init, w_init, engine, **kwargs)
1495 w_init = new_grids[0]["w"].values.squeeze()
1497 if (
1498 engine.lower() == "scipy"
1499 or engine.lower() == "jax"
1500 or engine.lower() == "auglag"
1501 ):
-> 1502 return _get_dd_wind_field_scipy(
1503 new_grids, u_init, v_init, w_init, engine, **kwargs
1504 )
1505 elif engine.lower() == "tensorflow":
1506 return _get_dd_wind_field_tensorflow(
1507 new_grids, u_init, v_init, w_init, **kwargs
1508 )
File ~/work/PyDDA/PyDDA/pydda/retrieval/wind_retrieve.py:614, in _get_dd_wind_field_scipy(Grids, u_init, v_init, w_init, engine, points, vel_name, refl_field, u_back, v_back, z_back, frz, Co, Cm, Cx, Cy, Cz, Cb, Cv, Cmod, Cpoint, cvtol, gtol, Jveltol, Ut, Vt, low_pass_filter, mask_outside_opt, weights_obs, weights_model, weights_bg, max_iterations, mask_w_outside_opt, filter_window, filter_order, min_bca, max_bca, upper_bc, model_fields, output_cost_functions, roi, wind_tol, tolerance, const_boundary_cond, max_wind_mag, parallel)
612 parameters.print_out = False
613 if engine.lower() == "scipy":
--> 614 winds = fmin_l_bfgs_b(
615 J_function,
616 winds,
617 args=(parameters,),
618 maxiter=max_iterations,
619 pgtol=tolerance,
620 bounds=bounds,
621 fprime=grad_J,
622 callback=_vert_velocity_callback,
623 )
624 else:
626 def loss_and_gradient(x):
File /usr/share/miniconda/envs/pydda-docs/lib/python3.14/site-packages/scipy/optimize/_lbfgsb_py.py:281, in fmin_l_bfgs_b(func, x0, fprime, args, approx_grad, bounds, m, factr, pgtol, epsilon, iprint, maxfun, maxiter, disp, callback, maxls)
269 callback = _wrap_callback(callback)
270 opts = {'disp': disp,
271 'iprint': iprint,
272 'maxcor': m,
(...) 278 'callback': callback,
279 'maxls': maxls}
--> 281 res = _minimize_lbfgsb(fun, x0, args=args, jac=jac, bounds=bounds,
282 **opts)
283 d = {'grad': res['jac'],
284 'task': res['message'],
285 'funcalls': res['nfev'],
286 'nit': res['nit'],
287 'warnflag': res['status']}
288 f = res['fun']
File /usr/share/miniconda/envs/pydda-docs/lib/python3.14/site-packages/scipy/optimize/_lbfgsb_py.py:469, in _minimize_lbfgsb(fun, x0, args, jac, bounds, disp, maxcor, ftol, gtol, eps, maxfun, maxiter, iprint, callback, maxls, finite_diff_rel_step, workers, **unknown_options)
461 _lbfgsb.setulb(m, x, low_bnd, upper_bnd, nbd, f, g, factr, pgtol, wa,
462 iwa, task, lsave, isave, dsave, maxls, ln_task)
464 if task[0] == 3:
465 # The minimization routine wants f and g at the current x.
466 # Note that interruptions due to maxfun are postponed
467 # until the completion of the current minimization iteration.
468 # Overwrite f and g:
--> 469 f, g = func_and_grad(x)
470 elif task[0] == 1:
471 # new iteration
472 n_iterations += 1
File /usr/share/miniconda/envs/pydda-docs/lib/python3.14/site-packages/scipy/optimize/_differentiable_functions.py:412, in ScalarFunction.fun_and_grad(self, x)
410 if not np.array_equal(x, self.x):
411 self._update_x(x)
--> 412 self._update_fun()
413 self._update_grad()
414 return self.f, self.g
File /usr/share/miniconda/envs/pydda-docs/lib/python3.14/site-packages/scipy/optimize/_differentiable_functions.py:362, in ScalarFunction._update_fun(self)
360 def _update_fun(self):
361 if not self.f_updated:
--> 362 fx = self._wrapped_fun(self.x)
363 self._nfev += 1
364 if fx < self._lowest_f:
File /usr/share/miniconda/envs/pydda-docs/lib/python3.14/site-packages/scipy/_lib/_util.py:603, in _ScalarFunctionWrapper.__call__(self, x)
600 def __call__(self, x):
601 # Send a copy because the user may overwrite it.
602 # The user of this class might want `x` to remain unchanged.
--> 603 fx = self.f(np.copy(x), *self.args)
604 self.nfev += 1
606 # Make sure the function returns a true scalar
File ~/work/PyDDA/PyDDA/pydda/cost_functions/cost_functions.py:193, in J_function(winds, parameters)
189 # print("apples Jvel", Jvel)
191 if parameters.Cm > 0:
192 # Had to change to float because Jax returns device array (use np.float_())
--> 193 Jmass = _cost_functions_numpy.calculate_mass_continuity(
194 winds[0],
195 winds[1],
196 winds[2],
197 parameters.z,
198 parameters.dx,
199 parameters.dy,
200 parameters.dz,
201 coeff=parameters.Cm,
202 )
203 else:
204 Jmass = 0
File ~/work/PyDDA/PyDDA/pydda/cost_functions/_cost_functions_numpy.py:454, in calculate_mass_continuity(u, v, w, z, dx, dy, dz, coeff, anel)
451 anel_term = np.zeros(w.shape)
452 div = dudx + dvdy + dwdz + anel_term
--> 454 return coeff * np.sum(np.square(div)) / 2.0
KeyboardInterrupt: