Ejemplo n.º 1
0
    def process_contour(self, ds: xr.Dataset, y_ind, x_ind):
        
        """ Redefine contour so that each point on the contour defined by
        y_ind and x_ind is seperated from its neighbours by a single index change 
        in y or x, but not both. 
        example: convert y_ind = [10,11], x_ind = [1,2] to y_ind = [10,10], x_ind = [1,2]
        or  y_ind = [10,11], x_ind = [1,1]
         
        Parameters
        ----------
        nemo : xarray.Dataset
            xarray Dataset from supplied nemo object
        y_ind : numpy.ndarray
            1d array of y indices defining the contour on the model grid
        x_ind : numpy.ndarray
            1d array of x indices defining the contour on the model grid

        Returns
        -------
        y_ind : numpy.ndarray
            processed y indices of the contour on the model grid
        x_ind : numpy.ndarray
            processed x indices of the contour on the model grid
         
        """
         
        try:
            y_ind = np.asarray(y_ind)
            x_ind = np.asarray(x_ind)
            # When replacing diagonal segments in the contour, pick the path that is
            # closest to the contour isobath depth
            option1 = uf.fabs(ds.bathymetry[xr.DataArray(y_ind+1), xr.DataArray(x_ind)] - self.depth)
            option0 = uf.fabs(ds.bathymetry[xr.DataArray(y_ind), xr.DataArray(x_ind+1)] - self.depth)
            add_new_y_point = xr.where(option1 <= option0, 1, 0 )
        
            spacing = np.abs( np.diff(y_ind) ) + np.abs( np.diff(x_ind) )
            if spacing.max() > 2:
                raise ValueError("The contour is not continuous. The contour must be defined on " 
                                 "adjacent grid points.")
            spacing[spacing!=2]=0
            doublespacing = np.nonzero( spacing )[0]
            for ispacing in doublespacing[::-1]:
                if add_new_y_point[ispacing]:
                    y_ind = np.insert( y_ind, ispacing+1, y_ind[ispacing+1] )
                    x_ind = np.insert( x_ind, ispacing+1, x_ind[ispacing] )
                else:
                    y_ind = np.insert( y_ind, ispacing+1, y_ind[ispacing] )
                    x_ind = np.insert( x_ind, ispacing+1, x_ind[ispacing+1] ) 
            
            # Remove any repeated points caused by the rounding of the indices
            nonrepeated_idx = np.nonzero( np.abs( np.diff(y_ind) ) + np.abs( np.diff(x_ind) ) )
    
            y_ind = np.concatenate( (y_ind[nonrepeated_idx], [y_ind[-1]]) )
            x_ind = np.concatenate( (x_ind[nonrepeated_idx], [x_ind[-1]]) )
    
            return (y_ind, x_ind)
        except ValueError:
            print(traceback.format_exc())
Ejemplo n.º 2
0
def cfl_check(dataset, model_params):

    sagp.get_grid_sizes(dataset, model_params)

    dataset_2 = xruf.fabs(dataset['ucomp']) * model_params[
        'delta_t'] * model_params['res'] / model_params['planet_radius']

    dataset['cfl'] = (('time'), dataset_2.max(dim=('pfull', 'lat', 'lon')))
Ejemplo n.º 3
0
    def _get_earth_mask(lat):
        """Identify earth/space pixels

        Returns:
            Mask (1=earth, 0=space)
        """
        logger.debug('Computing earth mask')
        return xu.fabs(lat) <= 90
Ejemplo n.º 4
0
def normalized_copy(data):
    """
    Return a copy of data, with the absolute taken and normalized to 0-1.

    The maximum across all regions and timesteps is used to normalize.

    """
    ds = data.copy(deep=True)  # Work off a copy
    data_vars_in_t = [v for v in time_clustering._get_datavars(data)
                      if 't' in data[v].dims]
    for var in data_vars_in_t:
        for y in ds.coords['y'].values:
            # Get max across all regions to normalize against
            norm_max = fabs(ds[var].loc[{'y': y}]).max()
            for x in ds.coords['x'].values:
                df = ds[var].loc[{'x': x, 'y': y}]
                ds[var].loc[{'x': x, 'y': y}] = fabs(df) / norm_max
    return ds
 def getEndOfSeason(self, array, sMmaxgreen):
     # compute the minimum in the season start
     seasonEnd_Range=array.sel(t=slice(self.eStart,self.eEnd))
     seasonEnd_MinGreennessIdx=seasonEnd_Range.argmin('t')
     seasonEnd_DateAtMin,seasonEnd_MinGreenness=seasonEnd_Range.t[seasonEnd_MinGreennessIdx].dt.dayofyear,seasonEnd_Range.isel(t=seasonEnd_MinGreennessIdx)
     # Calculate the greenness value corresponding to the start of the season
     seasonEnd_Greenness = seasonEnd_MinGreenness + ((sMmaxgreen - seasonEnd_MinGreenness) * (self.tEos / 100.0))
     # Get the closest date to this greenness
     #for i in range(len(seasonEnd_Range[:])): seasonEnd_Range[i]=seasonEnd_Range[i]-seasonEnd_Greenness
     seasonEnd_Range=fabs(seasonEnd_Range-seasonEnd_Greenness)
     seasonEnd_Idx=seasonEnd_Range.where(seasonEnd_Range.t.dt.dayofyear<=seasonEnd_DateAtMin).argmin('t',skipna=True)
     seasonEnd_Date=seasonEnd_Range.t[seasonEnd_Idx].dt.dayofyear
     return seasonEnd_Date
Ejemplo n.º 6
0
    def _double_t_test(self, t0, dof):
        """
        Double tailed student t test.

        **Arguments:**
        *array*
        t0 field `xarray.DataArray`;
        dof `int`;

        **Return:**
        *array*
           p: p values;

        """

        from scipy.stats import t
        from xarray.ufuncs import fabs
        pvalue = 2 * t.sf(fabs(t0), dof) * xr.ones_like(t0)
        return pvalue
Ejemplo n.º 7
0
def plot_3d_isosurface(X, Y, Z, Q, level, is_ordered=False, fig=None,
                       **kwargs):
    """Plot a the surface of a given level value of Q

    Assumes Q approximately decreases/increases monotonically with depth

    Inputs
    ------
    X, Y, Z: 1D or 3D arrays
        The grid associated with Q
    Q: 3D array
        The quantity from which to find the isosurface
    level: float
        The value of the isosurface
    is_ordered: bool
        Set to true if Q(X, Y, Z) not Q(Z, Y, X), which is MITgcm default
    fig: figure instance
        If no figure instance is passed in, a new one is created
    kwargs: dict
        Values to pass to ?

    Output
    ------
    fig: figure instance
    surf: contour surface artist
    """
    fig = plt.figure() if fig is None else fig
    ax = fig.gca(projection='3d')

    Z_inds = np.argmin(fabs(Q - level), axis=0)
    Z_surface = Z.data[[Z_inds]].squeeze()
    print(Z_surface.shape)

    if X.ndim == 1 and Y.ndim == 1:
        X, Y = np.meshgrid(X, Y)

    # Quick hack to avoid edge effects
    inds = np.s_[5:-5, 5:-5]
    ax.plot_surface(X[inds], Y[inds], Z_surface[inds])

    return Z_inds
Ejemplo n.º 8
0
def plot_lid_driven_cavity_frame(Re, n):
    ds = xr.open_dataset(f"lid_driven_cavity_Re{Re}.nc", decode_times=False)
    Ny = ds.yC.size
    Nz = ds.zC.size

    fig, axes = plt.subplots(nrows=3, ncols=2, figsize=(16, 16), dpi=200)
    plt.subplots_adjust(hspace=0.25)
    fig.suptitle(f"Lid-driven cavity, Re = {Re}, t = {ds.time[n].values:.2f}",
                 fontsize=16)

    ax_v_line, ax_v_mesh = axes[0, 0], axes[0, 1]
    ax_w_line, ax_w_mesh = axes[1, 0], axes[1, 1]
    ax_ζ_line, ax_ζ_mesh = axes[2, 0], axes[2, 1]

    v_line = ds.v.isel(time=n, yF=Ny // 2)
    ax_v_line.plot(y_Ghia,
                   v_Ghia[Re],
                   label="Ghia et al. (1982)",
                   color="tab:blue",
                   linestyle="",
                   marker="o",
                   fillstyle="none")
    ax_v_line.plot(ds.zC,
                   v_line.values.flatten(),
                   label="Oceananigans.jl",
                   color="tab:blue")
    ax_v_line.legend(loc="lower left",
                     bbox_to_anchor=(0, 1.01, 1, 0.2),
                     ncol=2,
                     frameon=False)
    ax_v_line.set_xlabel("z")
    ax_v_line.set_ylabel("v")
    ax_v_line.set_xlim([0, 1])

    w_line = ds.w.isel(time=n, zF=Nz // 2)
    ax_w_line.plot(z_Ghia,
                   w_Ghia[Re],
                   label="Ghia et al. (1982)",
                   color="tab:orange",
                   linestyle="",
                   marker="o",
                   fillstyle="none")
    ax_w_line.plot(ds.yC,
                   w_line.values.flatten(),
                   label="Oceananigans.jl",
                   color="tab:orange")
    ax_w_line.legend(loc="lower left",
                     bbox_to_anchor=(0, 1.01, 1, 0.2),
                     ncol=2,
                     frameon=False)
    ax_w_line.set_xlabel("y")
    ax_w_line.set_ylabel("w")
    ax_w_line.set_xlim([0, 1])

    v = ds.v.isel(time=n).squeeze()
    img_v = v.plot.pcolormesh(ax=ax_v_mesh,
                              vmin=-1,
                              vmax=1,
                              cmap=cmocean.cm.balance,
                              add_colorbar=False)
    fig.colorbar(img_v, ax=ax_v_mesh, extend="both")
    ax_v_mesh.axvline(x=0.5, color="tab:blue", alpha=0.5)
    ax_v_mesh.set_title("v-velocity")
    ax_v_mesh.set_xlabel("y")
    ax_v_mesh.set_ylabel("z")
    ax_v_mesh.set_aspect("equal")

    w = ds.w.isel(time=n).squeeze()
    img_w = w.plot.pcolormesh(ax=ax_w_mesh,
                              vmin=-1,
                              vmax=1,
                              cmap=cmocean.cm.balance,
                              add_colorbar=False)
    fig.colorbar(img_w, ax=ax_w_mesh, extend="both")
    ax_w_mesh.axhline(y=0.5, color="tab:orange", alpha=0.5)
    ax_w_mesh.set_title("w-velocity")
    ax_w_mesh.set_xlabel("y")
    ax_w_mesh.set_ylabel("z")
    ax_w_mesh.set_aspect("equal")

    ζ_line = fabs(ds.ζ.isel(time=n, zF=Nz))
    ax_ζ_line.plot(y_ζ_Ghia,
                   ζ_Ghia[Re],
                   label="Ghia et al. (1982)",
                   color="tab:purple",
                   linestyle="",
                   marker="o",
                   fillstyle="none")
    ax_ζ_line.plot(ds.yF,
                   ζ_line.values.flatten(),
                   label="Oceananigans.jl",
                   color="tab:purple")
    ax_ζ_line.legend(loc="lower left",
                     bbox_to_anchor=(0, 1.01, 1, 0.2),
                     ncol=2,
                     frameon=False)
    ax_ζ_line.set_xlabel("y")
    ax_ζ_line.set_ylabel("vorticity $|\zeta$|")
    ax_ζ_line.set_xlim([0, 1])
    ax_ζ_line.set_ylim(bottom=0)

    ζ = ds.ζ.isel(time=n).squeeze()
    img_ζ = ζ.plot.pcolormesh(ax=ax_ζ_mesh,
                              cmap=cmocean.cm.curl,
                              extend="both",
                              add_colorbar=False,
                              norm=colors.SymLogNorm(base=10,
                                                     linthresh=1,
                                                     vmin=-1e2,
                                                     vmax=1e2))
    fig.colorbar(img_ζ, ax=ax_ζ_mesh, extend="both")
    ax_ζ_mesh.axhline(y=1, color="tab:purple", alpha=1.0)
    ax_ζ_mesh.set_title("vorticity")
    ax_ζ_mesh.set_xlabel("y")
    ax_ζ_mesh.set_ylabel("z")
    ax_ζ_mesh.set_aspect("equal")

    print(f"Saving lid-driven cavity Re={Re} frame {n}/{ds.time.size-1}...")
    plt.savefig(f"lid_driven_cavity_Re{Re}_{n:05d}.png")
    plt.close("all")