Quiver plots of eddies' center translation speed about py-eddy-tracker

[AntSimi]

Hi,
You could look here to see an example of use.
add_fields will create a new dataset with the new field which must be filled.

Nevertheless several method like grid_stat accept field name or array with same size than dataset.

Antoine

[acapet]

Thanks,

But a2 = a.add_fields(("dx",)) throws the following error.

---

Exception Traceback (most recent call last)
in
----> 1 a2=a.add_fields(("dx",))

~/.pyenv/versions/3.8.3/lib/python3.8/site-packages/pyEddyTracker-3.3.0+4.g40ce202.dirty-py3.8.egg/py_eddy_tracker/observations/observation.py in add_fields(self, fields, array_fields)
316 """
317 nb_obs = self.obs.shape[0]
--> 318 new = self.class(
319 size=nb_obs,
320 track_extra_variables=list(

~/.pyenv/versions/3.8.3/lib/python3.8/site-packages/pyEddyTracker-3.3.0+4.g40ce202.dirty-py3.8.egg/py_eddy_tracker/observations/tracking.py in init(self, *args, **kwargs)
66
67 def init(self, *args, **kwargs):
---> 68 super().init(*args, **kwargs)
69 self.__first_index_of_track = None
70 self.__obs_by_track = None

~/.pyenv/versions/3.8.3/lib/python3.8/site-packages/pyEddyTracker-3.3.0+4.g40ce202.dirty-py3.8.egg/py_eddy_tracker/observations/observation.py in init(self, size, track_extra_variables, track_array_variables, array_variables, only_variables, raw_data)
162 for elt in self.elements:
163 if elt not in VAR_DESCR:
--> 164 raise Exception("Unknown element : %s" % elt)
165 self.observations = zeros(size, dtype=self.dtype)
166 self.sign_type = None

Exception: Unknown element : dx

[acapet]

and (for the second suggestion)

extent = [27, 42, 40.5, 47]
bins = ((extent[0], extent[1], step), (extent[2], extent[3], step))
g = a.grid_stat(bins, dx)

also cause some troubles :

---

TypeError Traceback (most recent call last)
in
----> 1 g = a.grid_stat(bins, dx)

~/.pyenv/versions/3.8.3/lib/python3.8/site-packages/pyEddyTracker-3.3.0+4.g40ce202.dirty-py3.8.egg/py_eddy_tracker/observations/observation.py in grid_stat(self, bins, varname, data)
2010 x0 = bins[0][0]
2011 x, y = (self.longitude - x0) % 360 + x0, self.latitude
-> 2012 data = self[varname] if data is None else data
2013 if hasattr(data, "mask"):
2014 m = ~data.mask

~/.pyenv/versions/3.8.3/lib/python3.8/site-packages/pyEddyTracker-3.3.0+4.g40ce202.dirty-py3.8.egg/py_eddy_tracker/observations/observation.py in getitem(self, attr)
286 if attr in self.elements:
287 return self.obs[attr]
--> 288 elif attr in VAR_DESCR_inv:
289 return self.obs[VAR_DESCR_inv[attr]]
290 elif attr in ("lifetime", "age"):

TypeError: unhashable type: 'numpy.ndarray'

although i have

print(dx.shape)
print(a["radius_e"].shape)
print(type(dx))
print(type(a["radius_e"]))

(26853,)
(26853,)
<class 'numpy.ndarray'>
<class 'numpy.ndarray'>

[AntSimi]

Ok sorry i answered too quickly.
So for grid_stat method use data option, in this case if you provide only varname the assumption is ouput grid name will be same than eddies dataset, if you use data option you could choose a name different for output grid and dataset variable.
For your second problem (i didn't think about that yesterday) actually you could only add known variable to be able to convert in netcdf and other things, ...
Antoine

[acapet]

Solved. For those interested, here's how it was done :

extent = [27, 42, 40.5, 47]
step = 0.25
bins = ((extent[0], extent[1], step), (extent[2], extent[3], step))

def dx_to_next(s):
    d = distance(
        s.longitude[:-1],
        s.latitude[:-1],
        s.longitude[1:],
        s.latitude[:-1],
        )
    d[s.longitude[1:]<s.longitude[:-1]] = - d[s.longitude[1:]<s.longitude[:-1]]
    d[s.index_from_track[1:] - 1] = 0
    d_ = np.empty(d.shape[0] + 1, dtype=d.dtype)
    d_[:-1] = d/86400
    d_[-1] = 0
    return d_

def dy_to_next(s):
    d = distance(
        s.longitude[:-1],
        s.latitude[:-1],
        s.longitude[:-1],
        s.latitude[1:],
        )
    d[s.latitude[1:]<s.latitude[:-1]] = - d[s.latitude[1:]<s.latitude[:-1]]
    d[s.index_from_track[1:] - 1] = 0
    d_ = np.empty(d.shape[0] + 1, dtype=d.dtype)
    d_[:-1] = d/86400
    d_[-1] = 0
    return d_


a = TrackEddiesObservations.load_file("../out_"+set1+"/Tracks_Overlap/Anticyclonic.nc")
a.position_filter(median_half_window=1, loess_half_window=5)

dxa=dx_to_next(a)
dya=dy_to_next(a)

ga = a.grid_stat(bins, varname='dx', data=dxa)
gay = a.grid_stat(bins, varname='dy', data=dya)
ga.add_grid("dy", gay.vars['dy'])

X=np.arange(bins[0][0]+bins[0][2]/2,bins[0][1]-bins[0][2]/2,bins[0][2])
Y=np.arange(bins[1][0]+bins[1][2]/2,bins[1][1]-bins[1][2]/2,bins[1][2])
[X,Y]=np.meshgrid(X,Y)

f = plt.figure(figsize=(12,10))

ax = start_axes("Anticyclonic dx", fig=f, sp='221')
m = ga.display(ax,name='dx', **kwargs_q)
update_axes(ax, m)

ax = start_axes("Anticyclonic dy", fig=f, sp='222')
m = ga.display(ax,name='dy', **kwargs_q)
update_axes(ax, m, 'm/s')

ax = start_axes("Anticyclonic Quiver", fig=f, sp='212')
Q=ax.quiver(x=X, y=Y, u=ga.vars['dx'].T, v=ga.vars['dy'].T,transform=ccrs.PlateCarree())
ax.quiverkey(Q=Q, X=.8, Y=.8, U=0.05, label='0.05 m/s', labelpos='E', coordinates="axes")