Changes in sasmodels/sesans.py [3c56da87:384d114] in sasmodels

File:

• sasmodels/sesans.py (modified) (2 diffs)

sasmodels/sesans.py

@@ -12 +12 @@
 import numpy as np
 from numpy import pi, exp
-
 from scipy.special import jv as besselj
 
-def make_q(q_zmax, Rmax):
+def make_q(q_max, Rmax):
+    r"""
+    Return a $q$ vector suitable for SESANS covering from $2\pi/ (10 R_{\max})$
+    to $q_max$.
+    """
     q_min = dq = 0.1 * 2*pi / Rmax
-    #q_min = 0.00003
-    return np.arange(q_min, q_zmax, dq)
-
-# TODO: dead code; for now the call to the hankel transform happens in BumpsModel
-class SesansCalculator:
-    def __init__(self, kernel, q_zmax, Rmax, SElength, wavelength, thickness):
-        self._set_kernel(kernel, q_zmax, Rmax)
-        self.SElength = SElength
-        self.wavelength = wavelength
-        self.thickness = thickness
-
-    def _set_kernel(self, kernel, q_zmax, Rmax):
-        kernel_input = kernel.make_input([make_q(q_zmax, Rmax)])
-        self.sans_calculator = kernel(kernel_input)
-
-    def __call__(self, pars, pd_pars, cutoff=1e-5):
-        Iq = self.sans_calculator(pars, pd_pars, cutoff)
-        P = hankel(self.SElength, self.wavelength, self.thickness, self.q, Iq)
-        self.Iq = Iq
-        return P
+    return np.arange(q_min, q_max, dq)
 
 def hankel(SElength, wavelength, thickness, q, Iq):
-    """
+    r"""
     Compute the expected SESANS polarization for a given SANS pattern.
 
-    Uses the hankel transform followed by the exponential.  The values
-    for zz (or spin echo length, or delta), wavelength and sample thickness
-    information should come from the dataset.  *q* should be chosen such
-    that the oscillations in *I(q)* are well sampled (e.g., 5*2*pi/d_max).
+    Uses the hankel transform followed by the exponential.  The values for *zz*
+    (or spin echo length, or delta), wavelength and sample thickness should
+    come from the dataset.  $q$ should be chosen such that the oscillations
+    in $I(q)$ are well sampled (e.g., $5 \cdot 2 \pi/d_{\max}$).
 
-    *SElength* [A] is the set of z points at which to compute the hankel transform
+    *SElength* [A] is the set of $z$ points at which to compute the
+    Hankel transform
 
     *wavelength* [m]  is the wavelength of each individual point *zz*
@@ -53 +38 @@
     *thickness* [cm] is the sample thickness.
 
-    *q* [A^{-1}] is the set of q points at which the model has been computed.
-    These should be equally spaced.
+    *q* [A$^{-1}$] is the set of $q$ points at which the model has been
+    computed. These should be equally spaced.
 
-    *I* [cm^{-1}] is the value of the SANS model at *q*
+    *I* [cm$^{-1}$] is the value of the SANS model at *q*
     """
     G = np.zeros(len(SElength), 'd')
     for i in range(len(SElength)):
-        integr = besselj(0,q*SElength[i])*Iq*q
+        integr = besselj(0, q*SElength[i])*Iq*q
         G[i] = np.sum(integr)
-    dq=(q[1]-q[0])*1e10   # [m^-1] step size in q, needed for integration
-    G *= dq*1e10*2*pi # integr step, conver q into [m**-1] and 2 pi circle integr
+
+    # [m^-1] step size in q, needed for integration
+    dq=(q[1]-q[0])*1e10
+
+    # integration step, convert q into [m**-1] and 2 pi circle integration
+    G *= dq*1e10*2*pi
+
     P = exp(thickness*wavelength**2/(4*pi**2)*(G-G[0]))