Changeset d07f863 in sasview for src/sas/sascalc

Timestamp:

Sep 16, 2017 10:50:38 PM (7 years ago)

Author:

GitHub <noreply@…>

Parents:

cfd27dd (diff), 0794ce3 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

git-author:

Lewis O'Driscoll <lewis.o'driscoll@…> (09/16/17 22:50:38)

git-committer:

GitHub <noreply@…> (09/16/17 22:50:38)

Message:

Merge 0794ce3ca2d0601bc623ffd5c74885b7383e69f4 into cfd27dd1bcdea96a621d51fbd290980fb6e6156a

Location:

src/sas/sascalc/corfunc

Files:

• corfunc_calculator.py (modified) (4 diffs)
• transform_thread.py (modified) (5 diffs)

src/sas/sascalc/corfunc/corfunc_calculator.py

@@ -34 +34 @@
 
         def __call__(self, x):
-            if self._lastx == [] or x.tolist() != self._lastx.tolist():
+            # If input is a single number, evaluate the function at that number
+            # and return a single number
+            if type(x) == float or type(x) == int:
+                return self._smoothed_function(np.array([x]))[0]
+            # If input is a list, and is different to the last input, evaluate
+            # the function at each point. If the input is the same as last time
+            # the function was called, return the result that was calculated
+            # last time instead of explicity evaluating the function again.
+            elif self._lastx == [] or x.tolist() != self._lastx.tolist():
                 self._lasty = self._smoothed_function(x)
                 self._lastx = x
@@ -121 +129 @@
         extrapolation = Data1D(qs, iqs)
 
-        return params, extrapolation
+        return params, extrapolation, s2
 
     def compute_transform(self, extrapolation, trans_type, background=None,
@@ -131 +139 @@
         :param background: The background value (if not provided, previously
             calculated value will be used)
+        :param extrap_fn: A callable function representing the extraoplated data
         :param completefn: The function to call when the transform calculation
             is complete`
@@ -144 +153 @@
         if trans_type == 'fourier':
             self._transform_thread = FourierThread(self._data, extrapolation,
-            background, completefn=completefn, updatefn=updatefn)
+            background, completefn=completefn,
+            updatefn=updatefn)
         elif trans_type == 'hilbert':
             self._transform_thread = HilbertThread(self._data, extrapolation,

src/sas/sascalc/corfunc/transform_thread.py

@@ -2 +2 @@
 from sas.sascalc.dataloader.data_info import Data1D
 from scipy.fftpack import dct
+from scipy.integrate import trapz
 import numpy as np
 from time import sleep
@@ -13 +14 @@
         self.extrapolation = extrapolated_data
 
+    def check_if_cancelled(self):
+        if self.isquit():
+            self.update("Fourier transform cancelled.")
+            self.complete(transforms=None)
+            return True
+        return False
+
     def compute(self):
         qs = self.extrapolation.x
@@ -19 +27 @@
         background = self.background
 
+        xs = np.pi*np.arange(len(qs),dtype=np.float32)/(q[1]-q[0])/len(qs)
+
         self.ready(delay=0.0)
-        self.update(msg="Starting Fourier transform.")
+        self.update(msg="Fourier transform in progress.")
         self.ready(delay=0.0)
-        if self.isquit():
-            return
+
+        if self.check_if_cancelled(): return
         try:
-            gamma = dct((iqs-background)*qs**2)
-            gamma = gamma / gamma.max()
-        except:
+            # ----- 1D Correlation Function -----
+            gamma1 = dct((iqs-background)*qs**2)
+            Q = gamma1.max()
+            gamma1 /= Q
+
+            if self.check_if_cancelled(): return
+
+            # ----- 3D Correlation Function -----
+            # gamma3(R) = 1/R int_{0}^{R} gamma1(x) dx
+            # trapz uses the trapezium rule to calculate the integral
+            mask = xs <= 200.0 # Only calculate gamma3 up to x=200 (as this is all that's plotted)
+            gamma3 = [trapz(gamma1[:n], xs[:n])/xs[n-1] for n in range(2, len(xs[mask]) + 1)]
+            gamma3.insert(0, 1.0) # Gamma_3(0) is defined as 1
+            gamma3 = np.array(gamma3)
+
+            if self.check_if_cancelled(): return
+
+            # ----- Interface Distribution function -----
+            idf = dct(-qs**4 * (iqs-background))
+
+            if self.check_if_cancelled(): return
+
+            # Manually calculate IDF(0.0), since scipy DCT tends to give us a
+            # very large negative value.
+            # IDF(x) = int_0^inf q^4 * I(q) * cos(q*x) * dq
+            # => IDF(0) = int_0^inf q^4 * I(q) * dq
+            idf[0] = trapz(-qs**4 * (iqs-background), qs)
+            idf /= Q # Normalise using scattering invariant
+
+        except Exception as e:
+            import logging
+            logger = logging.getLogger(__name__)
+            logger.error(e)
+
             self.update(msg="Fourier transform failed.")
-            self.complete(transform=None)
+            self.complete(transforms=None)
             return
         if self.isquit():
@@ -35 +76 @@
         self.update(msg="Fourier transform completed.")
 
-        xs = np.pi*np.arange(len(qs),dtype=np.float32)/(q[1]-q[0])/len(qs)
-        transform = Data1D(xs, gamma)
+        transform1 = Data1D(xs, gamma1)
+        transform3 = Data1D(xs[xs <= 200], gamma3)
+        idf = Data1D(xs, idf)
 
-        self.complete(transform=transform)
+        transforms = (transform1, transform3, idf)
+
+        self.complete(transforms=transforms)
 
 class HilbertThread(CalcThread):
@@ -64 +108 @@
         self.update(msg="Hilbert transform completed.")
 
-        self.complete(transform=None)
+        self.complete(transforms=None)