def test_argsel2d():
"""Check that function returns correct indices.
This compares with previous calculation."""
lon0, lat0 = -95.8, 27.1
assert xroms.argsel2d(ds.lon_rho, ds.lat_rho, lon0, lat0) == (0, 1)
assert xroms.argsel2d(ds.lon_psi, ds.lat_psi, lon0, lat0) == (0, 0)
assert xroms.argsel2d(ds.lon_u, ds.lat_u, lon0, lat0) == (0, 0)
assert xroms.argsel2d(ds.lon_v, ds.lat_v, lon0, lat0) == (0, 1)
assert xroms.argsel2d(ds.lon_vert, ds.lat_vert, lon0, lat0) == (1, 1)
def test_argsel2d():
'''Check that function returns correct indices.
This compares with previous calculation.'''
lon0, lat0 = -95.8, 27.1
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='rho') == (0, 1)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='psi') == (0, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='u') == (0, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='v') == (0, 1)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='vert') == (1, 1)
def test_argsel2d_exact():
"""test for exact index."""
lon0, lat0 = -95.928571, 27.166685 # one corner of grid
assert xroms.argsel2d(ds.lon_rho, ds.lat_rho, lon0, lat0) == (0, 0)
assert xroms.argsel2d(ds.lon_psi, ds.lat_psi, lon0, lat0) == (0, 0)
assert xroms.argsel2d(ds.lon_u, ds.lat_u, lon0, lat0) == (1, 0)
assert xroms.argsel2d(ds.lon_v, ds.lat_v, lon0, lat0) == (0, 0)
assert xroms.argsel2d(ds.lon_vert, ds.lat_vert, lon0, lat0) == (1, 1)
lon0, lat0 = -94.071429, 28.333351 # other corner of grid
assert xroms.argsel2d(ds.lon_rho, ds.lat_rho, lon0, lat0) == (7, 13)
assert xroms.argsel2d(ds.lon_psi, ds.lat_psi, lon0, lat0) == (7, 12)
assert xroms.argsel2d(ds.lon_u, ds.lat_u, lon0, lat0) == (8, 12)
assert xroms.argsel2d(ds.lon_v, ds.lat_v, lon0, lat0) == (7, 13)
assert xroms.argsel2d(ds.lon_vert, ds.lat_vert, lon0, lat0) == (8, 13)
def argsel2d(self, lon0, lat0):
"""Find the indices of coordinate pair closest to another point.
Inputs
------
lon0: float, int
Longitude of comparison point.
lat0: float, int
Latitude of comparison point.
Returns
-------
Indices in eta, xi of closest location to lon0, lat0.
Notes
-----
This function uses Great Circle distance to calculate distances assuming
longitudes and latitudes as point coordinates. Uses cartopy function
`Geodesic`: https://scitools.org.uk/cartopy/docs/latest/cartopy/geodesic.html
Example usage
-------------
>>> ds.temp.xroms.argsel2d(-96, 27)
"""
return xroms.argsel2d(self.da.cf["longitude"], self.da.cf["latitude"],
lon0, lat0)
def test_argsel2d_exact():
'''test for exact index.'''
lon0, lat0 = -95.928571, 27.166685 # one corner of grid
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='rho') == (1, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='psi') == (0, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='u') == (1, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='v') == (0, 0)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='vert') == (1, 1)
lon0, lat0 = -94.071429, 28.333351 # other corner of grid
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='rho') == (8, 13)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='psi') == (7, 12)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='u') == (8, 12)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='v') == (7, 13)
assert xroms.argsel2d(grid, lon0, lat0, whichgrid='vert') == (8, 13)
def test_argsel2d():
lon0, lat0 = -94.8, 28.0
testvars = ["salt", "u", "v", "z_w"]
for testvar in testvars:
inds = ds[testvar].xroms.argsel2d(lon0, lat0)
outinds = xroms.argsel2d(ds[testvar].cf["longitude"],
ds[testvar].cf["latitude"], lon0, lat0)
assert np.allclose(inds, outinds)