Changeset ccf58fb in sasview for src/sas/sascalc/corfunc/transform_thread.py

Timestamp:

Sep 11, 2017 6:08:09 AM (7 years ago)

Author:

lewis

Branches:

master, ESS_GUI, ESS_GUI_Docs, ESS_GUI_batch_fitting, ESS_GUI_bumps_abstraction, ESS_GUI_iss1116, ESS_GUI_iss879, ESS_GUI_iss959, ESS_GUI_opencl, ESS_GUI_ordering, ESS_GUI_sync_sascalc, magnetic_scatt, release-4.2.2, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, ticket885, unittest-saveload

Children:

0794ce3

Parents:

a309667 (diff), f9ba422 (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.

Message:

Merge branch 'master' into corfunc3d

File:

• src/sas/sascalc/corfunc/transform_thread.py (modified) (5 diffs)

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)