def _convert_units(self, key, values):
"""
Convert SEGY units to plot units.
"""
_units = self._get_units(key)
if _units is not None:
scl = float(units.__getattribute__(_units[0])\
/units.__getattribute__(_units[1]))
return [v * scl for v in values]
else:
return values
def interface2netcdf(vm, iref, filename, units="km", elevation=False):
"""
Write interface depths to a netcdf file.
Parameters
----------
vm : :class:`rockfish.tomography.model.VM`
VM model to extract an interface from.
iref : int
Index of interface to extract.
filename: str
Name of the netcdf file to write the interface to.
units : 'str', optional
Name of distance units in the output file. Must be a unit name
understood by :class:`sympy.physics.units`. Distance units in the
model are assumed to be 'km'.
elevation : bool, optional
If ``True``, flip the sign of interface depths.
"""
# Unit scaling
scl = sunits.kilometers / sunits.__getattribute__(units)
if elevation:
zscl = scl * -1.0
else:
zscl = scl
# Open file
f = netcdf(filename, "w")
f.title = "Interface {:} from VM model.".format(iref)
f.source = "Created by rockfish.tomography.vm2gmt.surface2netcdf"
# x-dimension
f.createDimension("x", vm.ny)
x = f.createVariable("x", "f", ("x",))
x[:] = vm.y * scl
x.units = units
# y-dimension
f.createDimension("y", vm.nx)
y = f.createVariable("y", "f", ("y",))
y[:] = vm.x * scl
y.units = units
# depths (z)
z = f.createVariable("z", "f", ("x", "y"))
z[:, :] = vm.rf[iref].transpose() * zscl
z.units = units
z.scale_factor = 1.0
z.add_offset = 0.0
# depth range
f.createDimension("side", 2)
z_range = f.createVariable("z_range", "f", ("side",))
z_range[0] = np.min(vm.rf[0]) * zscl
z_range[1] = np.min(vm.rf[1]) * zscl
f.sync()
f.close()
