def test_parse_lon_lat():
grid_shape = (1, 1, 1)
grid_limits = ((0, 1), (0, 1), (0, 1))
grid = pyart.testing.make_empty_grid(grid_shape, grid_limits)
lon, lat = common.parse_lon_lat(grid, None, None)
assert_almost_equal(lon, -98.1, 2)
assert_almost_equal(lat, 36.74, 2)
lon, lat = common.parse_lon_lat(grid, -12.34, 56.78)
assert_almost_equal(lon, -12.34, 2)
assert_almost_equal(lat, 56.78, 2)
def test_parse_lon_lat():
grid_shape = (1, 1, 1)
grid_limits = ((0, 1), (0, 1), (0, 1))
grid = pyart.testing.make_empty_grid(grid_shape, grid_limits)
lon, lat = common.parse_lon_lat(grid, None, None)
assert_almost_equal(lon, -98.1, 2)
assert_almost_equal(lat, 36.74, 2)
lon, lat = common.parse_lon_lat(grid, -12.34, 56.78)
assert_almost_equal(lon, -12.34, 2)
assert_almost_equal(lat, 56.78, 2)
def plot_crosshairs(self,
lon=None,
lat=None,
linestyle='--',
color='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.
linestyle : str
Matplotlib string describing the line style.
color : str
Matplotlib string for color of the line.
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)
# add crosshairs
ax.axhline(lat, color=color, linestyle=linestyle, linewidth=linewidth)
ax.axvline(lon, color=color, linestyle=linestyle, linewidth=linewidth)
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
