"""
Freeform modeling with B-Splines
**DEPRECATED** Use refl1d.mono instead.
"""
import numpy as np
from numpy import inf
from bumps.parameter import Parameter as Par, to_dict
from bumps.bspline import pbs, bspline
from .model import Layer
from . import util
#TODO: add left_sld, right_sld to all layers so that fresnel works
#TODO: access left_sld, right_sld so freeform doesn't need left, right
#TODO: restructure to use vector parameters
#TODO: allow the number of layers to be adjusted by the fit
[docs]
class FreeLayer(Layer):
"""
A freeform section of the sample modeled with B-splines.
sld (rho) and imaginary sld (irho) can be modeled with a separate
number of control points. The control points can be equally spaced
in the layers unless rhoz or irhoz are specified. If the z values
are given, they must be in the range [0, 1]. One control point is
anchored at either end, so there are two fewer z values than controls
if z values are given.
Layers have a slope of zero at the ends, so the automatically blend
with slabs.
"""
def __init__(self, thickness=0, left=None, right=None,
rho=(), irho=(), rhoz=(), irhoz=(), name="Freeform"):
self.name = name
self.left, self.right = left, right
self.thickness = Par.default(thickness, limits=(0, inf),
name=name+" thickness")
self.rho, self.irho, self.rhoz, self.irhoz \
= [[Par.default(p, name=name+" [%d] %s"%(i, part), limits=limits)
for i, p in enumerate(v)]
for v, part, limits
in zip((rho, irho, rhoz, irhoz),
('rho', 'irho', 'rhoz', 'irhoz'),
((-inf, inf), (-inf, inf), (0, 1), (0, 1)))
]
if len(self.rhoz) > 0 and len(self.rhoz) != len(self.rho):
raise ValueError("must have one z value for each rho")
if len(self.irhoz) > 0 and len(self.irhoz) != len(self.irho):
raise ValueError("must have one z value for each irho")
[docs]
def parameters(self):
return {
'rho': self.rho,
'rhoz': self.rhoz,
'irho': self.irho,
'irhoz': self.irhoz,
# TODO: left/right pars are already listed in the stack
'left': self.left.parameters(),
'right': self.right.parameters(),
}
[docs]
def to_dict(self):
return to_dict({
'type': type(self).__name__,
'name': self.name,
'parameters': self.parameters(),
})
[docs]
def render(self, probe, slabs):
thickness = self.thickness.value
left_rho, left_irho = self.left.sld(probe)
right_rho, right_irho = self.right.sld(probe)
Pw, Pz = slabs.microslabs(thickness)
t = Pz/thickness
Prho = _profile(left_rho, right_rho, self.rho, self.rhoz, t)
Pirho = _profile(left_irho, right_irho, self.irho, self.irhoz, t)
slabs.extend(rho=[Prho], irho=[Pirho], w=Pw)
[docs]
class FreeInterface(Layer):
"""
A freeform section of the sample modeled with monotonic splines.
Layers have a slope of zero at the ends, so the automatically blend
with slabs.
"""
def __init__(self, interface=0,
below=None, above=None,
dz=None, dp=None, name="Interface"):
self.name = name
self.below, self.above = below, above
self.interface = Par.default(interface, limits=(0, inf),
name=name+" interface")
# Choose reasonable defaults if not given
if dp is None and dz is None:
dp = [1]*5
if dp is None:
dp = [1]*len(dz)
if dz is None:
dz = [10./len(dp)]*len(dp)
if len(dz) != len(dp):
raise ValueError("Need one dz for every dp")
#if len(z) != len(vf)+2:
# raise ValueError("Only need vf for interior z, so len(z)=len(vf)+2")
self.dz = [Par.default(p, name=name+" dz[%d]"%i, limits=(0, inf))
for i, p in enumerate(dz)]
self.dp = [Par.default(p, name=name+" dp[%d]"%i, limits=(0, inf))
for i, p in enumerate(dp)]
def _get_thickness(self):
w = sum(v.value for v in self.dz)
return Par(w, name=self.name+" thickness")
def _set_thickness(self, v):
if v != 0:
raise ValueError("thickness cannot be set for FreeInterface")
thickness = property(_get_thickness, _set_thickness)
[docs]
def parameters(self):
return {
'interface': self.interface,
'below': self.below.parameters(),
'above': self.above.parameters(),
'dz': self.dz,
'dp': self.dp,
}
[docs]
def to_dict(self):
return to_dict({
'type': type(self).__name__,
'name': self.name,
'parameters': self.parameters(),
})
[docs]
def render(self, probe, slabs):
left_rho, left_irho = self.below.sld(probe)
right_rho, right_irho = self.above.sld(probe)
z = np.hstack((0, np.cumsum([v.value for v in self.dz])))
p = np.hstack((0, np.cumsum([v.value for v in self.dp])))
if p[-1] == 0:
p[-1] = 1
p /= p[-1]
Pw, Pz = slabs.microslabs(z[-1])
_, profile = pbs(z, p, Pz, parametric=False, clamp=True)
profile = np.clip(profile, 0, 1)
Pw, profile = util.merge_ends(Pw, profile, tol=1e-3)
Prho = (1-profile)*left_rho + profile*right_rho
Pirho = (1-profile)*left_irho + profile*right_irho
slabs.extend(rho=[Prho], irho=[Pirho], w=Pw)
def _profile(left, right, control, z, t):
cy = np.hstack((left, [p.value for p in control], right))
if len(z) > 0:
cx = np.hstack((0, [p.value for p in z], 1))
return pbs(cx, cy, t)
else:
return bspline(cy, t)