def test_mercator_b_operation__defaults():
lceaop = MercatorBConversion()
assert lceaop.name == "unknown"
assert lceaop.method_name == "Mercator (variant B)"
assert _to_dict(lceaop) == {
"Latitude of 1st standard parallel": 0.0,
"Longitude of natural origin": 0.0,
"False easting": 0.0,
"False northing": 0.0,
}
def test_mercator_b_operation():
lceaop = MercatorBConversion(
latitude_first_parallel=1,
longitude_natural_origin=2,
false_easting=3,
false_northing=4,
)
assert lceaop.name == "unknown"
assert lceaop.method_name == "Mercator (variant B)"
assert _to_dict(lceaop) == {
"Latitude of 1st standard parallel": 1.0,
"Longitude of natural origin": 2.0,
"False easting": 3.0,
"False northing": 4.0,
}
def _mercator(cf_params):
"""
http://cfconventions.org/cf-conventions/cf-conventions.html#_mercator
"""
if "scale_factor_at_projection_origin" in cf_params:
return MercatorAConversion(
latitude_natural_origin=cf_params.get("standard_parallel", 0.0),
longitude_natural_origin=cf_params.get(
"longitude_of_projection_origin", 0.0
),
false_easting=cf_params.get("false_easting", 0.0),
false_northing=cf_params.get("false_northing", 0.0),
scale_factor_natural_origin=cf_params["scale_factor_at_projection_origin"],
)
return MercatorBConversion(
latitude_first_parallel=cf_params.get("standard_parallel", 0.0),
longitude_natural_origin=cf_params.get("longitude_of_projection_origin", 0.0),
false_easting=cf_params.get("false_easting", 0.0),
false_northing=cf_params.get("false_northing", 0.0),
)