Changeset 1759 for trunk

Timestamp:

Mar 23, 2015 4:21:36 PM (8 years ago)

Author:

vondreele

Message:

add two new background functions - power series in Q^{2 & 1/Q}2 - from old GSASIIpwd.py
fix errors in calculation of weights from incident intensity functions for old TOF data.

Location:

trunk

Files:

• GSASIIpwd.py (modified) (7 diffs)
• GSASIIpwdGUI.py (modified) (2 diffs)
• GSASIIstrMath.py (modified) (1 diff)

trunk/GSASIIpwd.py

@@ -521 +521 @@
 def getBackground(pfx,parmDict,bakType,dataType,xdata):
     'needs a doc string'
+    if 'T' in dataType:
+        q = 2.*np.pi*parmDict[pfx+'difC']/xdata
+    elif 'C' in dataType:
+        wave = parmDict.get(pfx+'Lam',parmDict.get(pfx+'Lam1',1.0))
+        q = 2.*np.pi*npsind(xdata/2.)/wave
     yb = np.zeros_like(xdata)
     nBak = 0
@@ -542 +547 @@
                 ybi = parmDict[key]*npcosd(xdata*iBak)
             yb += ybi
-            sumBk[0] = np.sum(ybi)
+        sumBk[0] = np.sum(yb)
+    elif bakType in ['Q^2 power series','Q^-2 powder series']:
+        QT = 1.
+        yb += np.ones_like(yb)*parmDict[pfx+'Back;0']
+        for iBak in range(nBak-1):
+            key = pfx+'Back;'+str(iBak+1)
+            if '-2' in bakType:
+                QT *= (iBak+1)*q**-2
+            else:
+                QT *= q**2/(iBak+1)
+            yb += QT*parmDict[key]
+        sumBk[0] = np.sum(yb)
     elif bakType in ['lin interpolate','inv interpolate','log interpolate',]:
         if nBak == 1:
@@ -574 +590 @@
         except KeyError:
             wave = parmDict[pfx+'Lam1']
-        q = 4.0*np.pi*npsind(xdata/2.0)/wave
         SQ = (q/(4.*np.pi))**2
         FF = G2elem.GetFormFactorCoeff('Si')[0]
@@ -628 +643 @@
 def getBackgroundDerv(hfx,parmDict,bakType,dataType,xdata):
     'needs a doc string'
+    if 'T' in dataType:
+        q = 2.*np.pi*parmDict[hfx+'difC']/xdata
+    elif 'C' in dataType:
+        wave = parmDict.get(hfx+'Lam',parmDict.get(hfx+'Lam1',1.0))
+        q = 2.*np.pi*npsind(xdata/2.)/wave
     nBak = 0
     while True:
@@ -648 +668 @@
             elif bakType == 'cosine':
                 dydb[iBak] = npcosd(xdata*iBak)
+    elif bakType in ['Q^2 power series','Q^-2 powder series']:
+        QT = 1.
+        dydb[0] = np.ones_like(xdata)
+        for iBak in range(nBak-1):
+            if '-2' in bakType:
+                QT *= (iBak+1)*q**-2
+            else:
+                QT *= q**2/(iBak+1)
+            dydb[iBak+1] = QT
     elif bakType in ['lin interpolate','inv interpolate','log interpolate',]:
         if nBak == 1:
@@ -1608 +1637 @@
         x = xdata/1000.                 #expressions are in ms
         if Itype == 'Exponential':
-            for i in range(1,10,2):
+            for i in [1,3,5,7,9]:
                 Eterm = np.exp(-Icoef[i+1]*x**((i+1)/2))
                 YI += Icoef[i]*Eterm
                 DYI[i] *= Eterm
-                DYI[i+1] *= -Icoef[i]*x**((i+1)/2)            
+                DYI[i+1] *= -Icoef[i]*Eterm*x**((i+1)/2)            
         elif 'Maxwell'in Itype:
             Eterm = np.exp(-Icoef[2]/x**2)
@@ -1623 +1652 @@
                     YI += Icoef[i]*Eterm
                     DYI[i] *= Eterm
-                    DYI[i+1] *= -Icoef[i]*x**((i+1)/2)
+                    DYI[i+1] *= -Icoef[i]*Eterm*x**((i+1)/2)
             else:   #Chebyschev
                 T = (2./x)-1.

trunk/GSASIIpwdGUI.py

@@ -982 +982 @@
     G2frame.Bind(wx.EVT_MENU,OnBackFlagCopy,id=G2gd.wxID_BACKFLAGCOPY)
     BackId = G2gd.GetPatternTreeItemId(G2frame,G2frame.PatternId, 'Background')
-    Choices = ['chebyschev','cosine','lin interpolate','inv interpolate','log interpolate']
+    Choices = ['chebyschev','cosine','Q^2 power series','Q^-2 powder series','lin interpolate','inv interpolate','log interpolate']
     mainSizer = wx.BoxSizer(wx.VERTICAL)
     mainSizer.Add(BackSizer())
@@ -1464 +1464 @@
                     fmt = '%10.3f'
                     if 'beta' in item:
-                        fmt = '%12.4g'
-                        nDig = (12,4)
+                        fmt = '%12.6g'
+                        nDig = (12,6)
                     Fmt = ' %s: ('+fmt+')'
                     instSizer.Add(

trunk/GSASIIstrMath.py

@@ -1324 +1324 @@
 def GetPwdrExtDerv(refl,im,pfx,phfx,hfx,calcControls,parmDict):
     'Needs a doc string'
-    delt = 0.001
+    delt = 0.01
     parmDict[phfx+'Extinction'] += delt
     plus = GetPwdrExt(refl,im,pfx,phfx,hfx,calcControls,parmDict)