def load_co21_IRAM():
co21 = fits.open("/media/eric/Data_3/M33/co21/m33.ico.fits")[0]
new_wcs = drop_axis(drop_axis(WCS(co21.header), 3), 2)
co21_proj = Projection(co21.data.squeeze(), unit=u.K, wcs=new_wcs)
return co21, co21_proj
def get_prop_hdrs(self):
'''
Generate headers for the moments.
'''
bunits = [self.cube.unit, self.cube.spectral_axis.unit,
self.cube.spectral_axis.unit,
self.cube.unit * self.cube.spectral_axis.unit]
comments = ["Image of the Zeroth Moment",
"Image of the First Moment",
"Image of the Second Moment",
"Image of the Integrated Intensity"]
self.prop_headers = []
self.prop_err_headers = []
for i in range(len(bunits)):
wcs = self.cube.wcs.copy()
new_wcs = drop_axis(wcs, -1)
hdr = new_wcs.to_header()
hdr_err = new_wcs.to_header()
hdr["BUNIT"] = bunits[i].to_string()
hdr_err["BUNIT"] = bunits[i].to_string()
hdr["COMMENT"] = comments[i]
hdr_err["COMMENT"] = comments[i] + " Error."
self.prop_headers.append(hdr)
self.prop_err_headers.append(hdr_err)
def get_prop_hdrs(self):
'''
Generate headers for the moments.
'''
bunits = [self.cube.unit, self.cube.spectral_axis.unit,
self.cube.spectral_axis.unit,
self.cube.unit * self.cube.spectral_axis.unit]
comments = ["Image of the Zeroth Moment",
"Image of the First Moment",
"Image of the Second Moment",
"Image of the Integrated Intensity"]
self.prop_headers = []
self.prop_err_headers = []
for i in range(len(bunits)):
wcs = self.cube.wcs.copy()
new_wcs = drop_axis(wcs, -1)
hdr = new_wcs.to_header()
hdr_err = new_wcs.to_header()
hdr["BUNIT"] = bunits[i].to_string()
hdr_err["BUNIT"] = bunits[i].to_string()
hdr["COMMENT"] = comments[i]
hdr_err["COMMENT"] = comments[i] + " Error."
self.prop_headers.append(hdr)
self.prop_err_headers.append(hdr_err)
def moment1_error(cube, scale, axis=0, how='auto', moment0=None, moment1=None):
'''
Compute the first moment error.
Parameters
----------
cube : SpectralCube
Data cube.
scale : SpectralCube or `~astropy.units.Quantity`
The noise level in the data, either as a single value (with the same
units as the cube) or a SpectralCube of noise values.
axis : int
Axis to compute moment over.
how : {'auto', 'cube', 'slice'}, optional
The computational method to use.
Returns
-------
moment1_err : `~spectral_cube.lower_dimensional_structures.Projection`
'''
if how == "auto":
how = iterator_strategy(cube, 0)
if how == "ray":
warn("Automatically selected 'ray' which isn't implemented. Using"
" 'slice' instead.")
how = 'slice'
# Compute moments if they aren't given.
if moment0 is None:
moment0 = cube.moment0(how=how, axis=axis)
if moment1 is None:
moment1 = cube.moment1(how=how, axis=axis)
# Remove velocity offset from centroid to match cube._pix_cen
# Requires converting to a Quantity
moment1 = u.Quantity(moment1)
moment1 -= cube.spectral_axis[0]
if how == "cube":
moment1_err = _cube1(cube, axis, scale, moment0, moment1)
elif how == "slice":
moment1_err = _slice1(cube, axis, scale, moment0, moment1)
else:
raise ValueError("how must be 'cube' or 'slice'.")
meta = {'moment_order': 1, 'moment_axis': axis, 'moment_method': how}
cube_meta = cube.meta.copy()
meta.update(cube_meta)
new_wcs = drop_axis(cube._wcs, np2wcs[axis])
return Projection(moment1_err,
copy=False,
wcs=new_wcs,
meta=meta,
header=cube._nowcs_header)
def moment1_error(cube, scale, axis=0, how='auto', moment0=None, moment1=None):
'''
Compute the first moment error.
Parameters
----------
cube : SpectralCube
Data cube.
scale : SpectralCube or `~astropy.units.Quantity`
The noise level in the data, either as a single value (with the same
units as the cube) or a SpectralCube of noise values.
axis : int
Axis to compute moment over.
how : {'auto', 'cube', 'slice'}, optional
The computational method to use.
Returns
-------
moment1_err : `~spectral_cube.lower_dimensional_structures.Projection`
'''
if how == "auto":
how = iterator_strategy(cube, 0)
if how == "ray":
warn("Automatically selected 'ray' which isn't implemented. Using"
" 'slice' instead.")
how = 'slice'
# Compute moments if they aren't given.
if moment0 is None:
moment0 = cube.moment0(how=how, axis=axis)
if moment1 is None:
moment1 = cube.moment1(how=how, axis=axis)
# Remove velocity offset from centroid to match cube._pix_cen
# Requires converting to a Quantity
moment1 = u.Quantity(moment1)
moment1 -= cube.spectral_axis[0]
if how == "cube":
moment1_err = _cube1(cube, axis, scale, moment0, moment1)
elif how == "slice":
moment1_err = _slice1(cube, axis, scale, moment0, moment1)
else:
raise ValueError("how must be 'cube' or 'slice'.")
meta = {'moment_order': 1,
'moment_axis': axis,
'moment_method': how}
cube_meta = cube.meta.copy()
meta.update(cube_meta)
new_wcs = drop_axis(cube._wcs, np2wcs[axis])
return Projection(moment1_err, copy=False, wcs=new_wcs, meta=meta,
header=cube._nowcs_header)
def moment0_error(cube, scale, axis=0, how='auto'):
'''
Compute the zeroth moment error.
Parameters
----------
cube : SpectralCube
Data cube.
scale : SpectralCube or `~astropy.units.Quantity`
The noise level in the data, either as a single value (with the same
units as the cube) or a SpectralCube of noise values.
axis : int
Axis to compute moment over.
how : {'auto', 'cube', 'slice'}, optional
The computational method to use.
Returns
-------
moment0 : `~spectral_cube.lower_dimensional_structures.Projection`
'''
if how == "auto":
how = iterator_strategy(cube, 0)
if how == "ray":
warn("Automatically selected 'ray' which isn't implemented. Using"
" 'slice' instead.")
how = 'slice'
if how == "cube":
moment0_err = _cube0(cube, axis, scale)
elif how == "slice":
moment0_err = _slice0(cube, axis, scale)
else:
raise ValueError("how must be 'cube' or 'slice'.")
# Multiply by spectral unit
moment0_err *= cube.spectral_axis.unit
meta = {'moment_order': 0,
'moment_axis': axis,
'moment_method': how}
cube_meta = cube.meta.copy()
meta.update(cube_meta)
new_wcs = drop_axis(cube._wcs, np2wcs[axis])
return Projection(moment0_err, copy=False, wcs=new_wcs, meta=meta,
header=cube._nowcs_header)
