Source code for pyart.graph.gridmapdisplay_basemap

"""
A class for plotting grid objects with a basemap.

"""

import warnings

import numpy as np
import matplotlib.pyplot as plt
try:
    from mpl_toolkits.basemap import Basemap
    from mpl_toolkits.basemap import pyproj
    _BASEMAP_AVAILABLE = True
except ImportError:
    _BASEMAP_AVAILABLE = False

from . import common
from ..exceptions import MissingOptionalDependency
from ..core.transforms import _interpolate_axes_edges


[docs]class GridMapDisplayBasemap(object): """ A class for creating plots from a grid object on top of a Basemap. Parameters ---------- grid : Grid Grid with data which will be used to create plots. debug : bool True to print debugging messages, False to supress them. Attributes ---------- grid : Grid Grid object. debug : bool True to print debugging messages, False to supressed them. basemap : Basemap Last plotted basemap, None when no basemap has been plotted. mappables : list List of ContourSet, etc. which have been plotted, useful when adding colorbars. fields : list List of fields which have been plotted. """ def __init__(self, grid, debug=False): """ initalize the object. """ # check that basemap is available if not _BASEMAP_AVAILABLE: raise MissingOptionalDependency( "Basemap is required to use GridMapDisplay but is not " + "installed") # set attributes self.grid = grid self.debug = debug self.mappables = [] self.fields = [] self.origin = 'origin' self.basemap = None
[docs] def plot_basemap( self, lat_lines=None, lon_lines=None, resolution='l', area_thresh=10000, auto_range=True, min_lon=-92, max_lon=-86, min_lat=40, max_lat=44, ax=None, **kwargs): """ Plot a basemap. Parameters ---------- lat_lines, lon_lines : array or None Locations at which to draw latitude and longitude lines. None will use default values which are reasonable for maps of North America. auto_range : bool True to determine map ranges from the latitude and longitude limits of the grid. False will use the min_lon, max_lon, min_lat, and max_lat parameters for the map range. min_lat, max_lat, min_lon, max_lon : float Latitude and longitude ranges for the map projection region in degrees. These parameter are not used if auto_range is True. resolution : 'c', 'l', 'i', 'h', or 'f'. Resolution of boundary database to use. See Basemap documentation for details. area_thresh : int Basemap area_thresh parameter. See Basemap documentation. ax : axes or None. Axis to add the basemap to, if None the current axis is used. kwargs: Basemap options Options to be passed to Basemap. If projection is not specified here it uses proj='merc' (mercator). """ # make basemap self._make_basemap(resolution, area_thresh, auto_range, min_lon, max_lon, min_lat, max_lat, ax, **kwargs) # parse the parameters if lat_lines is None: lat_lines = np.arange(30, 46, 1) if lon_lines is None: lon_lines = np.arange(-110, -75, 1) self.basemap.drawcoastlines(linewidth=1.25) self.basemap.drawstates() self.basemap.drawparallels( lat_lines, labels=[True, False, False, False]) self.basemap.drawmeridians( lon_lines, labels=[False, False, False, True])
[docs] def plot_grid( self, field, level=0, vmin=None, vmax=None, norm=None, cmap=None, mask_outside=False, title=None, title_flag=True, axislabels=(None, None), axislabels_flag=False, colorbar_flag=True, colorbar_label=None, colorbar_orient='vertical', edges=True, ax=None, fig=None, ticks=None, ticklabs=None, **kwargs): """ Plot the grid onto the current basemap. Additional arguments are passed to Basemaps's pcolormesh function. Parameters ---------- field : str Field to be plotted. level : int Index corresponding to the height level to be plotted. vmin, vmax : float Lower and upper range for the colormesh. If either parameter is None, a value will be determined from the field attributes (if available) or the default values of -8, 64 will be used. Parameters are ignored is norm is not None. norm : Normalize or None, optional matplotlib Normalize instance used to scale luminance data. If not None the vmax and vmin parameters are ignored. If None, vmin and vmax are used for luminance scaling. cmap : str or None Matplotlib colormap name. None will use the default colormap for the field being plotted as specified by the Py-ART configuration. mask_outside : bool True to mask data outside of vmin, vmax. False performs no masking. title : str Title to label plot with, None to use default title generated from the field and level parameters. Parameter is ignored if title_flag is False. title_flag : bool True to add a title to the plot, False does not add a title. axislabels : (str, str) 2-tuple of x-axis, y-axis labels. None for either label will use the default axis label. Parameter is ignored if axislabels_flag is False. axislabels_flag : bool True to add label the axes, False does not label the axes. colorbar_flag : bool True to add a colorbar with label to the axis. False leaves off the colorbar. colorbar_label : str Colorbar label, None will use a default label generated from the field information. colorbar_orient : 'vertical' or 'horizontal' Colorbar orientation. edges : bool True will interpolate and extrapolate the gate edges from the range, azimuth and elevations in the radar, treating these as specifying the center of each gate. False treats these coordinates themselved as the gate edges, resulting in a plot in which the last gate in each ray and the entire last ray are not not plotted. ax : Axis Axis to plot on. None will use the current axis. fig : Figure Figure to add the colorbar to. None will use the current figure. ticks : array Colorbar custom tick label locations. ticklabs : array Colorbar custom tick labels. """ # parse parameters ax, fig = common.parse_ax_fig(ax, fig) vmin, vmax = common.parse_vmin_vmax(self.grid, field, vmin, vmax) cmap = common.parse_cmap(cmap, field) basemap = self.get_basemap() data = self.grid.fields[field]['data'][level] # mask the data where outside the limits if mask_outside: data = np.ma.masked_invalid(data) data = np.ma.masked_outside(data, vmin, vmax) # plot the grid lons, lats = self.grid.get_point_longitude_latitude(edges=edges) if norm is not None: # if norm is set do not override with vmin/vmax vmin = vmax = None pm = basemap.pcolormesh( lons, lats, data, vmin=vmin, vmax=vmax, cmap=cmap, norm=norm, latlon=True, **kwargs) self.mappables.append(pm) self.fields.append(field) if title_flag: if title is None: ax.set_title(self.generate_grid_title(field, level)) else: ax.set_title(title) if axislabels_flag: self._label_axes_grid(axislabels, ax) if colorbar_flag: self.plot_colorbar( mappable=pm, label=colorbar_label, orientation=colorbar_orient, field=field, ax=ax, fig=fig, ticks=ticks, ticklabs=ticklabs) return
[docs] def plot_crosshairs( self, lon=None, lat=None, line_style='r--', linewidth=2, ax=None): """ Plot crosshairs at a given longitude and latitude. Parameters ---------- lon, lat : float Longitude and latitude (in degrees) where the crosshairs should be placed. If None the center of the grid is used. line_style : str Matplotlib string describing the line style. linewidth : float Width of markers in points. ax : axes or None. Axis to add the crosshairs to, if None the current axis is used. """ # parse the parameters ax = common.parse_ax(ax) lon, lat = common.parse_lon_lat(self.grid, lon, lat) basemap = self.get_basemap() # add crosshairs. x_lon, y_lon = basemap( np.array([lon, lon]), np.array([basemap.latmin, basemap.latmax])) x_lat, y_lat = basemap( np.array([basemap.lonmin, basemap.lonmax]), np.array([lat, lat])) ax.plot(x_lon, y_lon, line_style, linewidth=linewidth) ax.plot(x_lat, y_lat, line_style, linewidth=linewidth) return
[docs] def plot_latitude_slice(self, field, lon=None, lat=None, **kwargs): """ Plot a slice along a given latitude. For documentation of additional arguments see :py:func:`plot_latitudinal_level`. Parameters ---------- field : str Field to be plotted. lon, lat : float Longitude and latitude (in degrees) specifying the slice. If None the center of the grid is used. """ # parse parameters _, y_index = self._find_nearest_grid_indices(lon, lat) self.plot_latitudinal_level(field=field, y_index=y_index, **kwargs)
[docs] def plot_latitudinal_level( self, field, y_index, vmin=None, vmax=None, norm=None, cmap=None, mask_outside=False, title=None, title_flag=True, axislabels=(None, None), axislabels_flag=True, colorbar_flag=True, colorbar_label=None, colorbar_orient='vertical', edges=True, ax=None, fig=None, ticks=None, ticklabs=None, **kwargs): """ Plot a slice along a given latitude. Additional arguments are passed to Basemaps's pcolormesh function. Parameters ---------- field : str Field to be plotted. y_index : float Index of the latitudinal level to plot. vmin, vmax : float Lower and upper range for the colormesh. If either parameter is None, a value will be determined from the field attributes (if available) or the default values of -8, 64 will be used. Parameters are ignored is norm is not None. norm : Normalize or None, optional matplotlib Normalize instance used to scale luminance data. If not None the vmax and vmin parameters are ignored. If None, vmin and vmax are used for luminance scaling. cmap : str or None Matplotlib colormap name. None will use the default colormap for the field being plotted as specified by the Py-ART configuration. mask_outside : bool True to mask data outside of vmin, vmax. False performs no masking. title : str Title to label plot with, None to use default title generated from the field and lat,lon parameters. Parameter is ignored if title_flag is False. title_flag : bool True to add a title to the plot, False does not add a title. axislabels : (str, str) 2-tuple of x-axis, y-axis labels. None for either label will use the default axis label. Parameter is ignored if axislabels_flag is False. axislabels_flag : bool True to add label the axes, False does not label the axes. colorbar_flag : bool True to add a colorbar with label to the axis. False leaves off the colorbar. colorbar_label : str Colorbar label, None will use a default label generated from the field information. colorbar_orient : 'vertical' or 'horizontal' Colorbar orientation. edges : bool True will interpolate and extrapolate the gate edges from the range, azimuth and elevations in the radar, treating these as specifying the center of each gate. False treats these coordinates themselved as the gate edges, resulting in a plot in which the last gate in each ray and the entire last ray are not not plotted. ax : Axis Axis to plot on. None will use the current axis. fig : Figure Figure to add the colorbar to. None will use the current figure. ticks : array Colorbar custom tick label locations. ticklabs : array Colorbar custom tick labels. """ # parse parameters ax, fig = common.parse_ax_fig(ax, fig) vmin, vmax = common.parse_vmin_vmax(self.grid, field, vmin, vmax) cmap = common.parse_cmap(cmap, field) data = self.grid.fields[field]['data'][:, y_index, :] # mask the data where outside the limits if mask_outside: data = np.ma.masked_invalid(data) data = np.ma.masked_outside(data, vmin, vmax) # plot the grid x_1d = self.grid.x['data'] / 1000. z_1d = self.grid.z['data'] / 1000. if edges: if len(x_1d) > 1: x_1d = _interpolate_axes_edges(x_1d) if len(z_1d) > 1: z_1d = _interpolate_axes_edges(z_1d) xd, yd = np.meshgrid(x_1d, z_1d) if norm is not None: # if norm is set do not override with vmin/vmax vmin = vmax = None pm = ax.pcolormesh( xd, yd, data, vmin=vmin, vmax=vmax, norm=norm, cmap=cmap, **kwargs) self.mappables.append(pm) self.fields.append(field) if title_flag: if title is None: ax.set_title(common.generate_latitudinal_level_title( self.grid, field, y_index)) else: ax.set_title(title) if axislabels_flag: self._label_axes_latitude(axislabels, ax) if colorbar_flag: self.plot_colorbar( mappable=pm, label=colorbar_label, orientation=colorbar_orient, field=field, ax=ax, fig=fig, ticks=ticks, ticklabs=ticklabs) return
[docs] def plot_longitude_slice(self, field, lon=None, lat=None, **kwargs): """ Plot a slice along a given longitude. For documentation of additional arguments see :py:func:`plot_longitudinal_level`. Parameters ---------- field : str Field to be plotted. lon, lat : float Longitude and latitude (in degrees) specifying the slice. If None the center of the grid is used. """ x_index, _ = self._find_nearest_grid_indices(lon, lat) self.plot_longitudinal_level(field=field, x_index=x_index, **kwargs)
[docs] def plot_longitudinal_level( self, field, x_index, vmin=None, vmax=None, norm=None, cmap=None, mask_outside=False, title=None, title_flag=True, axislabels=(None, None), axislabels_flag=True, colorbar_flag=True, colorbar_label=None, colorbar_orient='vertical', edges=True, ax=None, fig=None, ticks=None, ticklabs=None, **kwargs): """ Plot a slice along a given longitude. Additional arguments are passed to Basemaps's pcolormesh function. Parameters ---------- field : str Field to be plotted. x_index : float Index of the longitudinal level to plot. vmin, vmax : float Lower and upper range for the colormesh. If either parameter is None, a value will be determined from the field attributes (if available) or the default values of -8, 64 will be used. Parameters are ignored is norm is not None. norm : Normalize or None, optional matplotlib Normalize instance used to scale luminance data. If not None the vmax and vmin parameters are ignored. If None, vmin and vmax are used for luminance scaling. cmap : str or None Matplotlib colormap name. None will use the default colormap for the field being plotted as specified by the Py-ART configuration. mask_outside : bool True to mask data outside of vmin, vmax. False performs no masking. title : str Title to label plot with, None to use default title generated from the field and lat,lon parameters. Parameter is ignored if title_flag is False. title_flag : bool True to add a title to the plot, False does not add a title. axislabels : (str, str) 2-tuple of x-axis, y-axis labels. None for either label will use the default axis label. Parameter is ignored if axislabels_flag is False. axislabels_flag : bool True to add label the axes, False does not label the axes. colorbar_flag : bool True to add a colorbar with label to the axis. False leaves off the colorbar. colorbar_label : str Colorbar label, None will use a default label generated from the field information. colorbar_orient : 'vertical' or 'horizontal' Colorbar orientation. edges : bool True will interpolate and extrapolate the gate edges from the range, azimuth and elevations in the radar, treating these as specifying the center of each gate. False treats these coordinates themselved as the gate edges, resulting in a plot in which the last gate in each ray and the entire last ray are not not plotted. ax : Axis Axis to plot on. None will use the current axis. fig : Figure Figure to add the colorbar to. None will use the current figure. ticks : array Colorbar custom tick label locations. ticklabs : array Colorbar custom tick labels. """ # parse parameters ax, fig = common.parse_ax_fig(ax, fig) vmin, vmax = common.parse_vmin_vmax(self.grid, field, vmin, vmax) cmap = common.parse_cmap(cmap, field) data = self.grid.fields[field]['data'][:, :, x_index] # mask the data where outside the limits if mask_outside: data = np.ma.masked_invalid(data) data = np.ma.masked_outside(data, vmin, vmax) # plot the grid y_1d = self.grid.y['data'] / 1000. z_1d = self.grid.z['data'] / 1000. if edges: if len(y_1d) > 1: y_1d = _interpolate_axes_edges(y_1d) if len(z_1d) > 1: z_1d = _interpolate_axes_edges(z_1d) xd, yd = np.meshgrid(y_1d, z_1d) if norm is not None: # if norm is set do not override with vmin/vmax vmin = vmax = None pm = ax.pcolormesh( xd, yd, data, vmin=vmin, vmax=vmax, cmap=cmap, norm=norm, **kwargs) self.mappables.append(pm) self.fields.append(field) if title_flag: if title is None: ax.set_title(common.generate_longitudinal_level_title( self.grid, field, x_index)) else: ax.set_title(title) if axislabels_flag: self._label_axes_longitude(axislabels, ax) if colorbar_flag: self.plot_colorbar( mappable=pm, label=colorbar_label, orientation=colorbar_orient, field=field, ax=ax, fig=fig, ticks=ticks, ticklabs=ticklabs) return
[docs] def plot_colorbar( self, mappable=None, orientation='horizontal', label=None, cax=None, ax=None, fig=None, field=None, ticks=None, ticklabs=None): """ Plot a colorbar. Parameters ---------- mappable : Image, ContourSet, etc. Image, ContourSet, etc to which the colorbar applied. If None the last mappable object will be used. field : str Field to label colorbar with. label : str Colorbar label. None will use a default value from the last field plotted. orient : str Colorbar orientation, either 'vertical' [default] or 'horizontal'. cax : Axis Axis onto which the colorbar will be drawn. None is also valid. ax : Axes Axis onto which the colorbar will be drawn. None is also valid. fig : Figure Figure to place colorbar on. None will use the current figure. ticks : array Colorbar custom tick label locations. ticklabs : array Colorbar custom tick labels. """ if fig is None: fig = plt.gcf() if mappable is None: if len(self.mappables) == 0: raise ValueError('mappable must be specified.') else: mappable = self.mappables[-1] if label is None: if len(self.fields) == 0: raise ValueError('field must be specified.') field = self.grid.fields[self.fields[-1]] if 'long_name' in field and 'units' in field: label = field['long_name'] + '(' + field['units'] + ')' else: label = '' # plot the colorbar and set the label. cb = fig.colorbar(mappable, orientation=orientation, ax=ax, cax=cax) if ticks is not None: cb.set_ticks(ticks) if ticklabs is not None: cb.set_ticklabels(ticklabs) cb.set_label(label) return
def _make_basemap( self, resolution='l', area_thresh=10000, auto_range=True, min_lon=-92, max_lon=-86, min_lat=40, max_lat=44, ax=None, **kwargs): """ Make a basemap. Parameters ---------- auto_range : bool True to determine map ranges from the latitude and longitude limits of the grid. False will use the min_lon, max_lon, min_lat, and max_lat parameters for the map range. min_lat, max_lat, min_lon, max_lon : float Latitude and longitude ranges for the map projection region in degrees. These parameter are not used if auto_range is True. resolution : 'c', 'l', 'i', 'h', or 'f'. Resolution of boundary database to use. See Basemap documentation for details. area_thresh : int Basemap area_thresh parameter. See Basemap documentation. ax : axes or None. Axis to add the basemap to, if None the current axis is used. kwargs : Basemap options Options to be passed to Basemap. If projection is not specified here it uses proj='merc' (mercator). """ # parse the parameters ax = common.parse_ax(ax) # determine map region if auto_range: max_lat = self.grid.point_latitude['data'][0].max() max_lon = self.grid.point_longitude['data'][0].max() min_lat = self.grid.point_latitude['data'][0].min() min_lon = self.grid.point_longitude['data'][0].min() if self.debug: print("Maximum latitude: ", max_lat) print("Maximum longitude: ", max_lon) print("Minimum latitude: ", min_lat) print("Minimum longitute: ", min_lon) # determine plot center lat_0 = self.grid.origin_latitude['data'][0] lon_0 = self.grid.origin_longitude['data'][0] default_args = { 'lat_0': lat_0, 'lon_0': lon_0, 'lat_ts': lat_0, 'projection': 'merc', 'area_thresh': area_thresh, 'resolution': resolution, 'ax': ax} using_corners = (None not in [min_lon, min_lat, max_lon, max_lat]) if using_corners: default_args['llcrnrlon'] = min_lon default_args['llcrnrlat'] = min_lat default_args['urcrnrlon'] = max_lon default_args['urcrnrlat'] = max_lat else: # determine width and height of the plot x = self.grid.x['data'][0] y = self.grid.y['data'][0] default_args['width'] = (x.max() - x.min()) default_args['height'] = (y.max() - y.min()) for key in default_args.keys(): if key not in kwargs: kwargs[key] = default_args[key] # plot the basemap self.basemap = Basemap(**kwargs) return self.basemap def _find_nearest_grid_indices(self, lon, lat): """ Find the nearest x, y grid indices for a given latitude and longitude. """ # A similar method would make a good addition to the Grid class itself lon, lat = common.parse_lon_lat(self.grid, lon, lat) grid_lons, grid_lats = self.grid.get_point_longitude_latitude() diff = (grid_lats - lat)**2 + (grid_lons - lon)**2 y_index, x_index = np.unravel_index(diff.argmin(), diff.shape) return x_index, y_index ########################## # Plot adjusting methods # ########################## def _get_label_x(self): """ Get default label for x units. """ return 'East West distance from ' + self.origin + ' (km)' def _get_label_y(self): """ Get default label for y units. """ return 'North South distance from ' + self.origin + ' (km)' def _get_label_z(self): """ Get default label for z units. """ return 'Distance Above ' + self.origin + ' (km)' def _label_axes_grid(self, axis_labels, ax): """ Set the x and y axis labels for a grid plot. """ x_label, y_label = axis_labels if x_label is None: x_label = self._get_label_x() if y_label is None: y_label = self._get_label_y() ax.set_xlabel(x_label) ax.set_ylabel(y_label) def _label_axes_longitude(self, axis_labels, ax): """ Set the x and y axis labels for a longitude slice. """ x_label, y_label = axis_labels if x_label is None: x_label = self._get_label_y() if y_label is None: y_label = self._get_label_z() ax.set_xlabel(x_label) ax.set_ylabel(y_label) def _label_axes_latitude(self, axis_labels, ax): """ Set the x and y axis labels for a latitude slice. """ x_label, y_label = axis_labels if x_label is None: x_label = self._get_label_x() if y_label is None: y_label = self._get_label_z() ax.set_xlabel(x_label) ax.set_ylabel(y_label) ########################## # name generator methods # ##########################
[docs] def generate_filename(self, field, level, ext='png'): """ Generate a filename for a grid plot. Generated filename has form: grid_name_field_level_time.ext Parameters ---------- field : str Field plotted. level : int Level plotted. ext : str Filename extension. Returns ------- filename : str Filename suitable for saving a plot. """ return common.generate_grid_filename(self.grid, field, level, ext)
[docs] def generate_grid_title(self, field, level): """ Generate a title for a plot. Parameters ---------- field : str Field plotted. level : int Verical level plotted. Returns ------- title : str Plot title. """ return common.generate_grid_title(self.grid, field, level)
[docs] def generate_longitudinal_level_title(self, field, level): """ Generate a title for a plot. Parameters ---------- field : str Field plotted. level : int Longitudinal level plotted. Returns ------- title : str Plot title. """ return common.generate_longitudinal_level_title( self.grid, field, level)
[docs] def generate_latitudinal_level_title(self, field, level): """ Generate a title for a plot. Parameters ---------- field : str Field plotted. level : int Longitudinal level plotted. Returns ------- title : str Plot title. """ return common.generate_latitudinal_level_title( self.grid, field, level)
########################## # get methods # ##########################
[docs] def get_basemap(self): """ get basemap of the plot """ if self.basemap is None: self._make_basemap() return self.basemap