def _path2chi(path, paramgroup=None, _larch=None, **kws):
"""calculate chi(k) for a Feff Path,
optionally setting path parameter values
output chi array will be written to path group
Parameters:
------------
path: a FeffPath Group
paramgroup: a Parameter Group for calculating Path Parameters [None]
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
None - outputs are written to path group
"""
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
if _larch is not None:
if (paramgroup is not None and _larch.symtable.isgroup(paramgroup)):
_larch.symtable._sys.paramGroup = paramgroup
elif not hasattr(_larch.symtable._sys, 'paramGroup'):
_larch.symtable._sys.paramGroup = Group()
path._calc_chi(**kws)
def _path2chi(path, paramgroup=None, _larch=None, **kws):
"""calculate chi(k) for a Feff Path,
optionally setting path parameter values
output chi array will be written to path group
Parameters:
------------
path: a FeffPath Group
paramgroup: a Parameter Group for calculating Path Parameters [None]
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
None - outputs are written to path group
"""
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
if _larch is not None:
if (paramgroup is not None and
_larch.symtable.isgroup(paramgroup)):
_larch.symtable._sys.paramGroup = paramgroup
elif not hasattr(_larch.symtable._sys, 'paramGroup'):
_larch.symtable._sys.paramGroup = Group()
path._calc_chi(**kws)
def _residual(self, paramgroup, data_only=False, **kws):
"""return the residual for this data set
residual = self.transform.apply(data_chi - model_chi)
where model_chi is the result of ff2chi(pathlist)
"""
if not isNamedClass(self.transform, TransformGroup):
return
if not self.__prepared:
self.prepare_fit()
_ff2chi(self.pathlist,
paramgroup=paramgroup,
k=self.model.k,
_larch=self._larch,
group=self.model)
eps_k = self.epsilon_k
if isinstance(eps_k, np.ndarray):
eps_k[np.where(eps_k < 1.e-12)[0]] = 1.e-12
diff = (self.__chi - self.model.chi)
if data_only: # for extracting transformed data separately from residual
diff = self.__chi
trans = self.transform
k = trans.k_[:len(diff)]
all_kweights = isinstance(trans.kweight, Iterable)
if trans.fitspace == 'k':
iqmin = max(0, int(0.01 + trans.kmin / trans.kstep))
iqmax = min(trans.nfft / 2, int(0.01 + trans.kmax / trans.kstep))
if all_kweights:
out = []
for i, kw in enumerate(trans.kweight):
out.append(((diff / eps_k[i]) * k**kw)[iqmin:iqmax])
return np.concatenate(out)
else:
return ((diff / eps_k) * k**trans.kweight)[iqmin:iqmax]
else:
out = []
if all_kweights:
chir = [trans.fftf(diff, kweight=kw) for kw in trans.kweight]
eps_r = self.epsilon_r
else:
chir = [trans.fftf(diff)]
eps_r = [self.epsilon_r]
if trans.fitspace == 'r':
irmin = max(0, int(0.01 + trans.rmin / trans.rstep))
irmax = min(trans.nfft / 2,
int(0.01 + trans.rmax / trans.rstep))
for i, chir_ in enumerate(chir):
chir_ = chir_ / (eps_r[i])
out.append(realimag(chir_[irmin:irmax]))
else:
chiq = [trans.fftr(c) / eps for c, eps in zip(chir, eps_r)]
iqmin = max(0, int(0.01 + trans.kmin / trans.kstep))
iqmax = min(trans.nfft / 2,
int(0.01 + trans.kmax / trans.kstep))
for chiq_ in chiq:
out.append(realimag(chiq_[iqmin:iqmax])[::2])
return np.concatenate(out)
def _residual(self, paramgroup=None, data_only=False, **kws):
"""return the residual for this data set
residual = self.transform.apply(data_chi - model_chi)
where model_chi is the result of ff2chi(pathlist)
"""
if (paramgroup is not None and
self._larch.symtable.isgroup(paramgroup)):
self._larch.symtable._sys.paramGroup = paramgroup
if not isNamedClass(self.transform, TransformGroup):
return
if not self.__prepared:
self.prepare_fit()
_ff2chi(self.pathlist, k=self.model.k,
_larch=self._larch, group=self.model)
eps_k = self.epsilon_k
if isinstance(eps_k, np.ndarray):
eps_k[np.where(eps_k<1.e-12)[0]] = 1.e-12
else:
eps_k = max(1.e-12, eps_k)
diff = (self.__chi - self.model.chi)
if data_only: # for extracting transformed data separately from residual
diff = self.__chi
trans = self.transform
k = trans.k_[:len(diff)]
all_kweights = isinstance(trans.kweight, Iterable)
if trans.fitspace == 'k':
iqmin = max(0, int(0.01 + trans.kmin/trans.kstep))
iqmax = min(trans.nfft/2, int(0.01 + trans.kmax/trans.kstep))
if all_kweights:
out = []
for i, kw in enumerate(trans.kweight):
out.append(((diff/eps_k[i])*k**kw)[iqmin:iqmax])
return np.concatenate(out)
else:
return ((diff/eps_k) * k**trans.kweight)[iqmin:iqmax]
else:
out = []
if all_kweights:
chir = [trans.fftf(diff, kweight=kw) for kw in trans.kweight]
eps_r = self.epsilon_r
else:
chir = [trans.fftf(diff)]
eps_r = [self.epsilon_r]
if trans.fitspace == 'r':
irmin = max(0, int(0.01 + trans.rmin/trans.rstep))
irmax = min(trans.nfft/2, int(0.01 + trans.rmax/trans.rstep))
for i, chir_ in enumerate(chir):
chir_ = chir_ / (eps_r[i])
out.append(realimag(chir_[irmin:irmax]))
else:
chiq = [trans.fftr(c)/eps for c, eps in zip(chir, eps_r)]
iqmin = max(0, int(0.01 + trans.kmin/trans.kstep))
iqmax = min(trans.nfft/2, int(0.01 + trans.kmax/trans.kstep))
for chiq_ in chiq:
out.append( realimag(chiq_[iqmin:iqmax])[::2])
return np.concatenate(out)
def _ff2chi(pathlist,
group=None,
paramgroup=None,
_larch=None,
k=None,
kmax=None,
kstep=0.05,
**kws):
"""sum chi(k) for a list of FeffPath Groups.
Parameters:
------------
pathlist: a list of FeffPath Groups
paramgroup: a Parameter Group for calculating Path Parameters [None]
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
group contain arrays for k and chi
This essentially calls path2chi() for each of the paths in the
pathlist and writes the resulting arrays to group.k and group.chi.
"""
msg = _larch.writer.write
if (paramgroup is not None and _larch is not None
and _larch.symtable.isgroup(paramgroup)):
_larch.symtable._sys.paramGroup = paramgroup
for path in pathlist:
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
path._calc_chi(k=k, kstep=kstep, kmax=kmax)
k = pathlist[0].k[:]
out = np.zeros_like(k)
for path in pathlist:
out += path.chi
if group is None:
group = Group()
else:
group = set_xafsGroup(group, _larch=_larch)
group.k = k
group.chi = out
return group
def _ff2chi(pathlist, group=None, paramgroup=None, _larch=None,
k=None, kmax=None, kstep=0.05, **kws):
"""sum chi(k) for a list of FeffPath Groups.
Parameters:
------------
pathlist: a list of FeffPath Groups
paramgroup: a Parameter Group for calculating Path Parameters [None]
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
group contain arrays for k and chi
This essentially calls path2chi() for each of the paths in the
pathlist and writes the resulting arrays to group.k and group.chi.
"""
msg = _larch.writer.write
if (paramgroup is not None and _larch is not None and
_larch.symtable.isgroup(paramgroup)):
_larch.symtable._sys.paramGroup = paramgroup
for path in pathlist:
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
path._calc_chi(k=k, kstep=kstep, kmax=kmax)
k = pathlist[0].k[:]
out = np.zeros_like(k)
for path in pathlist:
out += path.chi
if group is None:
group = Group()
else:
group = set_xafsGroup(group, _larch=_larch)
group.k = k
group.chi = out
return group
def _path2chi(path, paramgroup=None, _larch=None, **kws):
"""calculate chi(k) for a Feff Path,
optionally setting path parameter values
output chi array will be written to path group
Parameters:
------------
path: a FeffPath Group
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
None - outputs are written to path group
"""
params = group2params(paramgroup, _larch=_larch)
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
path.create_path_params()
path._calc_chi(**kws)
def path2chi(path, paramgroup=None, **kws):
"""calculate chi(k) for a Feff Path,
optionally setting path parameter values
output chi array will be written to path group
Parameters:
------------
path: a FeffPath Group
kmax: maximum k value for chi calculation [20].
kstep: step in k value for chi calculation [0.05].
k: explicit array of k values to calculate chi.
Returns:
---------
None - outputs are written to path group
"""
params = group2params(paramgroup)
if not isNamedClass(path, FeffPathGroup):
msg('%s is not a valid Feff Path' % path)
return
path.create_path_params(params=params)
path._calc_chi(**kws)
def feffit(paramgroup, datasets, rmax_out=10, path_outputs=True, _larch=None, **kws):
"""execute a Feffit fit: a fit of feff paths to a list of datasets
Parameters:
------------
paramgroup: group containing parameters for fit
datasets: Feffit Dataset group or list of Feffit Dataset group.
rmax_out: maximum R value to calculate output arrays.
path_output: Flag to set whether all Path outputs should be written.
Returns:
---------
a fit results group. This will contain subgroups of:
datasets: an array of FeffitDataSet groups used in the fit.
params: This will be identical to the input parameter group.
fit: an object which points to the low-level fit.
Statistical parameters will be put into the params group. Each
dataset will have a 'data' and 'model' subgroup, each with arrays:
k wavenumber array of k
chi chi(k).
kwin window Omega(k) (length of input chi(k)).
r uniform array of R, out to rmax_out.
chir complex array of chi(R).
chir_mag magnitude of chi(R).
chir_pha phase of chi(R).
chir_re real part of chi(R).
chir_im imaginary part of chi(R).
"""
def _resid(params, datasets=None, paramgroup=None, **kwargs):
""" this is the residual function"""
params2group(params, paramgroup)
return concatenate([d._residual(paramgroup) for d in datasets])
if isNamedClass(datasets, FeffitDataSet):
datasets = [datasets]
params = group2params(paramgroup, _larch=_larch)
for ds in datasets:
if not isNamedClass(ds, FeffitDataSet):
print( "feffit needs a list of FeffitDataSets")
return
ds.prepare_fit()
fit = Minimizer(_resid, params,
fcn_kws=dict(datasets=datasets,
paramgroup=paramgroup),
scale_covar=True, **kws)
result = fit.leastsq()
params2group(result.params, paramgroup)
dat = concatenate([d._residual(paramgroup, data_only=True) for d in datasets])
n_idp = 0
for ds in datasets:
n_idp += ds.n_idp
# here we rescale chi-square and reduced chi-square to n_idp
npts = len(result.residual)
chi_square = result.chisqr * n_idp*1.0 / npts
chi_reduced = chi_square/(n_idp*1.0 - result.nvarys)
rfactor = (result.residual**2).sum() / (dat**2).sum()
# calculate 'aic', 'bic' rescaled to n_idp
# note that neg2_loglikel is -2*log(likelihood)
neg2_loglikel = n_idp * np.log(chi_square / n_idp)
aic = neg2_loglikel + 2 * result.nvarys
bic = neg2_loglikel + np.log(n_idp) * result.nvarys
# With scale_covar = True, Minimizer() scales the uncertainties
# by reduced chi-square assuming params.nfree is the correct value
# for degrees-of-freedom. But n_idp-params.nvarys is a better measure,
# so we rescale uncertainties here.
covar = getattr(result, 'covar', None)
# print("COVAR " , covar)
if covar is not None:
err_scale = (result.nfree / (n_idp - result.nvarys))
for name in result.var_names:
p = result.params[name]
if isParameter(p) and p.vary:
p.stderr *= sqrt(err_scale)
# next, propagate uncertainties to constraints and path parameters.
result.covar *= err_scale
vsave, vbest = {}, []
# 1. save current params
for vname in result.var_names:
par = result.params[vname]
vsave[vname] = par
vbest.append(par.value)
# 2. get correlated uncertainties, set params accordingly
uvars = correlated_values(vbest, result.covar)
# 3. evaluate constrained params, save stderr
for nam, obj in result.params.items():
eval_stderr(obj, uvars, result.var_names, result.params)
# 3. evaluate path params, save stderr
for ds in datasets:
for p in ds.pathlist:
p.store_feffdat()
for pname in ('degen', 's02', 'e0', 'ei',
'deltar', 'sigma2', 'third', 'fourth'):
obj = p.params[PATHPAR_FMT % (pname, p.label)]
eval_stderr(obj, uvars, result.var_names, result.params)
# restore saved parameters again
for vname in result.var_names:
# setattr(params, vname, vsave[vname])
params[vname] = vsave[vname]
# clear any errors evaluting uncertainties
if _larch is not None and (len(_larch.error) > 0):
_larch.error = []
# reset the parameters group with the newly updated uncertainties
params2group(result.params, paramgroup)
# here we create outputs arrays for chi(k), chi(r):
for ds in datasets:
ds.save_ffts(rmax_out=rmax_out, path_outputs=path_outputs)
out = Group(name='feffit results', datasets=datasets,
fitter=fit, fit_details=result, chi_square=chi_square,
n_independent=n_idp, chi_reduced=chi_reduced,
rfactor=rfactor, aic=aic, bic=bic, covar=covar)
for attr in ('params', 'nvarys', 'nfree', 'ndata', 'var_names', 'nfev',
'success', 'errorbars', 'message', 'lmdif_message'):
setattr(out, attr, getattr(result, attr, None))
return out
def feffit(paramgroup, datasets, rmax_out=10, path_outputs=True, _larch=None, **kws):
"""execute a Feffit fit: a fit of feff paths to a list of datasets
Parameters:
------------
paramgroup: group containing parameters for fit
datasets: Feffit Dataset group or list of Feffit Dataset group.
rmax_out: maximum R value to calculate output arrays.
path_output: Flag to set whether all Path outputs should be written.
Returns:
---------
a fit results group. This will contain subgroups of:
datasets: an array of FeffitDataSet groups used in the fit.
params: This will be identical to the input parameter group.
fit: an object which points to the low-level fit.
Statistical parameters will be put into the params group. Each
dataset will have a 'data' and 'model' subgroup, each with arrays:
k wavenumber array of k
chi chi(k).
kwin window Omega(k) (length of input chi(k)).
r uniform array of R, out to rmax_out.
chir complex array of chi(R).
chir_mag magnitude of chi(R).
chir_pha phase of chi(R).
chir_re real part of chi(R).
chir_im imaginary part of chi(R).
"""
def _resid(params, datasets=None, paramgroup=None, **kwargs):
""" this is the residual function"""
params2group(params, paramgroup)
return concatenate([d._residual(paramgroup) for d in datasets])
if isNamedClass(datasets, FeffitDataSet):
datasets = [datasets]
params = group2params(paramgroup, _larch=_larch)
for ds in datasets:
if not isNamedClass(ds, FeffitDataSet):
print( "feffit needs a list of FeffitDataSets")
return
ds.prepare_fit()
fit = Minimizer(_resid, params,
fcn_kws=dict(datasets=datasets,
paramgroup=paramgroup),
scale_covar=True, **kws)
result = fit.leastsq()
params2group(result.params, paramgroup)
dat = concatenate([d._residual(paramgroup, data_only=True) for d in datasets])
n_idp = 0
for ds in datasets:
n_idp += ds.n_idp
# here we rescale chi-square and reduced chi-square to n_idp
npts = len(result.residual)
chi_square = result.chisqr * n_idp*1.0 / npts
chi_reduced = chi_square/(n_idp*1.0 - result.nvarys)
rfactor = (result.residual**2).sum() / (dat**2).sum()
# calculate 'aic', 'bic' rescaled to n_idp
# note that neg2_loglikel is -2*log(likelihood)
neg2_loglikel = n_idp * np.log(chi_square / n_idp)
aic = neg2_loglikel + 2 * result.nvarys
bic = neg2_loglikel + np.log(n_idp) * result.nvarys
# With scale_covar = True, Minimizer() scales the uncertainties
# by reduced chi-square assuming params.nfree is the correct value
# for degrees-of-freedom. But n_idp-params.nvarys is a better measure,
# so we rescale uncertainties here.
covar = getattr(result, 'covar', None)
# print("COVAR " , covar)
if covar is not None:
err_scale = (result.nfree / (n_idp - result.nvarys))
for name in result.var_names:
p = result.params[name]
if isParameter(p) and p.vary:
p.stderr *= sqrt(err_scale)
# next, propagate uncertainties to constraints and path parameters.
result.covar *= err_scale
vsave, vbest = {}, []
# 1. save current params
for vname in result.var_names:
par = result.params[vname]
vsave[vname] = par
vbest.append(par.value)
# 2. get correlated uncertainties, set params accordingly
uvars = correlated_values(vbest, result.covar)
# 3. evaluate constrained params, save stderr
for nam, obj in result.params.items():
eval_stderr(obj, uvars, result.var_names, result.params)
# 3. evaluate path params, save stderr
for ds in datasets:
for p in ds.pathlist:
p.store_feffdat()
for pname in ('degen', 's02', 'e0', 'ei',
'deltar', 'sigma2', 'third', 'fourth'):
obj = p.params[PATHPAR_FMT % (pname, p.label)]
eval_stderr(obj, uvars, result.var_names, result.params)
# restore saved parameters again
for vname in result.var_names:
# setattr(params, vname, vsave[vname])
params[vname] = vsave[vname]
# clear any errors evaluting uncertainties
if _larch is not None and (len(_larch.error) > 0):
_larch.error = []
# reset the parameters group with the newly updated uncertainties
params2group(result.params, paramgroup)
# here we create outputs arrays for chi(k), chi(r):
for ds in datasets:
ds.save_ffts(rmax_out=rmax_out, path_outputs=path_outputs)
out = Group(name='feffit results', datasets=datasets,
fitter=fit, fit_details=result, chi_square=chi_square,
n_independent=n_idp, chi_reduced=chi_reduced,
rfactor=rfactor, aic=aic, bic=bic, covar=covar)
for attr in ('params', 'nvarys', 'nfree', 'ndata', 'var_names', 'nfev',
'success', 'errorbars', 'message', 'lmdif_message'):
setattr(out, attr, getattr(result, attr, None))
return out
def feffit(params,
datasets,
_larch=None,
rmax_out=10,
path_outputs=True,
**kws):
"""execute a Feffit fit: a fit of feff paths to a list of datasets
Parameters:
------------
paramgroup: group containing parameters for fit
datasets: Feffit Dataset group or list of Feffit Dataset group.
rmax_out: maximum R value to calculate output arrays.
path_output: Flag to set whether all Path outputs should be written.
Returns:
---------
a fit results group. This will contain subgroups of:
datasets: an array of FeffitDataSet groups used in the fit.
params: This will be identical to the input parameter group.
fit: an object which points to the low-level fit.
Statistical parameters will be put into the params group. Each
dataset will have a 'data' and 'model' subgroup, each with arrays:
k wavenumber array of k
chi chi(k).
kwin window Omega(k) (length of input chi(k)).
r uniform array of R, out to rmax_out.
chir complex array of chi(R).
chir_mag magnitude of chi(R).
chir_pha phase of chi(R).
chir_re real part of chi(R).
chir_im imaginary part of chi(R).
"""
def _resid(params, datasets=None, _larch=None, **kwargs):
""" this is the residual function"""
return concatenate([d._residual() for d in datasets])
if isNamedClass(datasets, FeffitDataSet):
datasets = [datasets]
for ds in datasets:
if not isNamedClass(ds, FeffitDataSet):
print("feffit needs a list of FeffitDataSets")
return
fitkws = dict(datasets=datasets)
fit = Minimizer(_resid,
params,
fcn_kws=fitkws,
scale_covar=True,
_larch=_larch,
**kws)
fit.leastsq()
dat = concatenate([d._residual(data_only=True) for d in datasets])
params.rfactor = (params.fit_details.fvec**2).sum() / (dat**2).sum()
# remove temporary parameters for _feffdat and reff
# that had been placed by _pathparams()
#for pname in ('_feffdat', 'reff'):
# if hasattr(params, pname):
# delattr(params, pname)
n_idp = 0
for ds in datasets:
n_idp += ds.n_idp
# here we rescale chi-square and reduced chi-square to n_idp
npts = len(params.residual)
params.chi_square *= n_idp * 1.0 / npts
params.chi_reduced = params.chi_square / (n_idp * 1.0 - params.nvarys)
# With scale_covar = True, Minimizer() scales the uncertainties
# by reduced chi-square assuming params.nfree is the correct value
# for degrees-of-freedom. But n_idp-params.nvarys is a better measure,
# so we rescale uncertainties here.
covar = getattr(params, 'covar', None)
if covar is not None:
err_scale = (params.nfree / (n_idp - params.nvarys))
for name in dir(params):
p = getattr(params, name)
if isParameter(p) and p.vary:
p.stderr *= sqrt(err_scale)
# next, propagate uncertainties to constraints and path parameters.
params.covar *= err_scale
vsave, vbest = {}, []
# 1. save current params
for vname in params.covar_vars:
par = getattr(params, vname)
vsave[vname] = par
vbest.append(par.value)
# 2. get correlated uncertainties, set params accordingly
uvars = correlated_values(vbest, params.covar)
# 3. evaluate constrained params, save stderr
for nam in dir(params):
obj = getattr(params, nam)
eval_stderr(obj, uvars, params.covar_vars, vsave, _larch)
# 3. evaluate path params, save stderr
for ds in datasets:
for p in ds.pathlist:
_larch.symtable._sys.paramGroup._feffdat = copy(p._feffdat)
_larch.symtable._sys.paramGroup.reff = p._feffdat.reff
for param in ('degen', 's02', 'e0', 'ei', 'deltar', 'sigma2',
'third', 'fourth'):
obj = getattr(p, param)
eval_stderr(obj, uvars, params.covar_vars, vsave, _larch)
# restore saved parameters again
for vname in params.covar_vars:
setattr(params, vname, vsave[vname])
# clear any errors evaluting uncertainties
if len(_larch.error) > 0:
_larch.error = []
# here we create outputs arrays for chi(k), chi(r):
for ds in datasets:
ds.save_ffts(rmax_out=rmax_out, path_outputs=path_outputs)
return Group(name='feffit fit results',
fit=fit,
params=params,
datasets=datasets)
def feffit(params, datasets, _larch=None, rmax_out=10, path_outputs=True, **kws):
"""execute a Feffit fit: a fit of feff paths to a list of datasets
Parameters:
------------
paramgroup: group containing parameters for fit
datasets: Feffit Dataset group or list of Feffit Dataset group.
rmax_out: maximum R value to calculate output arrays.
path_output: Flag to set whether all Path outputs should be written.
Returns:
---------
a fit results group. This will contain subgroups of:
datasets: an array of FeffitDataSet groups used in the fit.
params: This will be identical to the input parameter group.
fit: an object which points to the low-level fit.
Statistical parameters will be put into the params group. Each
dataset will have a 'data' and 'model' subgroup, each with arrays:
k wavenumber array of k
chi chi(k).
kwin window Omega(k) (length of input chi(k)).
r uniform array of R, out to rmax_out.
chir complex array of chi(R).
chir_mag magnitude of chi(R).
chir_pha phase of chi(R).
chir_re real part of chi(R).
chir_im imaginary part of chi(R).
"""
def _resid(params, datasets=None, _larch=None, **kwargs):
""" this is the residual function"""
return concatenate([d._residual() for d in datasets])
if isNamedClass(datasets, FeffitDataSet):
datasets = [datasets]
for ds in datasets:
if not isNamedClass(ds, FeffitDataSet):
print( "feffit needs a list of FeffitDataSets")
return
fitkws = dict(datasets=datasets)
fit = Minimizer(_resid, params, fcn_kws=fitkws,
scale_covar=True, _larch=_larch, **kws)
fit.leastsq()
dat = concatenate([d._residual(data_only=True) for d in datasets])
params.rfactor = (params.fit_details.fvec**2).sum() / (dat**2).sum()
# remove temporary parameters for _feffdat and reff
# that had been placed by _pathparams()
#for pname in ('_feffdat', 'reff'):
# if hasattr(params, pname):
# delattr(params, pname)
n_idp = 0
for ds in datasets:
n_idp += ds.n_idp
# here we rescale chi-square and reduced chi-square to n_idp
npts = len(params.residual)
params.chi_square *= n_idp*1.0 / npts
params.chi_reduced = params.chi_square/(n_idp*1.0 - params.nvarys)
# With scale_covar = True, Minimizer() scales the uncertainties
# by reduced chi-square assuming params.nfree is the correct value
# for degrees-of-freedom. But n_idp-params.nvarys is a better measure,
# so we rescale uncertainties here.
covar = getattr(params, 'covar', None)
if covar is not None:
err_scale = (params.nfree / (n_idp - params.nvarys))
for name in dir(params):
p = getattr(params, name)
if isParameter(p) and p.vary:
p.stderr *= sqrt(err_scale)
# next, propagate uncertainties to constraints and path parameters.
params.covar *= err_scale
vsave, vbest = {}, []
# 1. save current params
for vname in params.covar_vars:
par = getattr(params, vname)
vsave[vname] = par
vbest.append(par.value)
# 2. get correlated uncertainties, set params accordingly
uvars = correlated_values(vbest, params.covar)
# 3. evaluate constrained params, save stderr
for nam in dir(params):
obj = getattr(params, nam)
eval_stderr(obj, uvars, params.covar_vars, vsave, _larch)
# 3. evaluate path params, save stderr
for ds in datasets:
for p in ds.pathlist:
_larch.symtable._sys.paramGroup._feffdat = copy(p._feffdat)
_larch.symtable._sys.paramGroup.reff = p._feffdat.reff
for param in ('degen', 's02', 'e0', 'ei',
'deltar', 'sigma2', 'third', 'fourth'):
obj = getattr(p, param)
eval_stderr(obj, uvars, params.covar_vars, vsave, _larch)
# restore saved parameters again
for vname in params.covar_vars:
setattr(params, vname, vsave[vname])
# clear any errors evaluting uncertainties
if len(_larch.error) > 0:
_larch.error = []
# here we create outputs arrays for chi(k), chi(r):
for ds in datasets:
ds.save_ffts(rmax_out=rmax_out, path_outputs=path_outputs)
return Group(name='feffit fit results', fit=fit, params=params,
datasets=datasets)
