Changeset 5151

Timestamp:

Jan 21, 2022 2:51:28 PM (21 months ago)

Author:

toby

Message:

improve seq. ref. constraint warning

Files:

• Tutorials/SeqRefine/SequentialTutorial.htm (modified) (9 diffs)
• trunk/GSASIIdataGUI.py (modified) (1 diff)

Tutorials/SeqRefine/SequentialTutorial.htm

@@ -2056 +2056 @@
 <P></P>
 <p class=MsoNormal>
-For the initial fitting of datasets over a range of conditions, we
-will want to start from the fitted values we have fit, but only refine
-a minimal number of parameters until the scale factor, background and
-lattice parameters have been optimized for each dataset and more
-variables can be added back. 
 <P></P>
 <p class=MsoNormal>There is one significant way that sequential
@@ -2070 +2065 @@
 
 <P></P>
-<p class=MsoNormal><I>
+<p class=MsoNormal style='PADDING-LEFT:0.25in'><I>
+More details: 
 Note that GSAS-II shows the user unit cell parameters in the
 traditional a, b, c, &#945;, &#946; & &#947; (distances in &#8491, angles in
@@ -2095 +2091 @@
 </I>
 
-
 <H3>1. Remove refinement of sensitive parameters (lattice, phase
 fractions, size/&#956;strain, background peak and sample displacement)
 and add refinement of the <tt>D<I>ij</i></tt> terms.</H3>
+
+<p class=MsoNormal style='PADDING-LEFT:0.25in'>
+For the initial fitting of datasets over a range of conditions, we
+will want to start from the fitted values we have fit, but until
+we have reasonably good values for the scale factor, background and
+lattice parameters, we do not want to refine any thing else.</P>
+
 
 <OL style='PADDING-LEFT:0.75in' type="A">
@@ -2460 +2462 @@
 src="SequentialTutorial_files/image075.png" v:shapes="Picture_x0020_77"><![endif]></span></p>
 
-<P></P><LI>
+  <P></P><LI>
+  <B><I>Important:</I></B>
   Check the "<b>Copy results to next histogram</b>?" checkbox. When this
   is selected, the parameters obtained after fitting each histogram
   will be used as the starting point for the next fit, which is
   essential here since the lattice parameters change considerably. If
-  this were not selected, then refinement of each histogram would
-  start with the current parameters -- that were obtained from fitting
-  the first (~7 K) dataset. 
-  The first few refinements will go well, but when reaching datasets
+  this were not selected, then refinement for <I>each histogram</I> would
+start with the current parameters for that histogram --
+these were obtained from fitting the first (~7 K) dataset. If we did that
+  the first few refinements will go well, but when reaching datasets
   where the temperature
   was sufficiently different from 7 K, the starting lattice parameters may be
   too far off and the refinements will fail. Even if that were not
-  true, since the temperatures increase in the series, the previous
-  histogram will have the closest set of lattice parameters and will
-  thus refine most quickly. </p>
+true, since the temperatures are fairly close between datasets in the
+series,
+each fit will start with a fairly close to correct set of lattice
+  parameters and thus fewer cycles of refinement will be needed to get
+  to the correct values. 
+</p>
 
 <P></P><LI>Also on the Controls window, change the <B>Max cycles</B>
@@ -2493 +2499 @@
 once the histograms were selected for a sequential fit in the previous
 step, the menu command was relabeled from Calculate/Sequential
-refine.) The refinement may take a few minutes as each of the 17
+refine.)</P><P></P>
+<p class=MsoListParagraphCxSpMiddle <p
+style='PADDING-LEFT:0.25in'><I>Note that a window
+saying "There were constraint warnings..." will be generated.
+This is because we have specified a constraint on the phase
+fractions in <A href="#I.3">step I.3</A>, but we are no longer varying
+them, so this constraint must be ignored.
+Also note the discussion on <A href="#VI.1.F">sequential fit
+constraint modes</A> in step VI, below. 
+This alert is shown to provide a chance to review
+possible problems with constraints and not continue with the fit,
+when this indicates that something has been left out from the varied
+parameters. However, in this case, this phase fraction constraint
+will be fine to ignore since we do not want to refine phase fractions
+at this stage. This message will stop being shown when phase fractions
+are refined again (or if the constraint would be removed). Press 
+"Yes" to continue with this initial sequential fit, as this
+warning can be ignored. 
+<P></P></I>
+<p class=MsoListParagraphCxSpMiddle>
+The refinement may take a few minutes as each of the 17
 datasets are fit in turn.</p>
-
-
 <h3>3. Accept the sequential refinement results.</h3>
 
@@ -2639 +2663 @@
 
   <P></P><LI>
+  <A name="VI.1.F"></A>
   Select the <B>Constraints</B> data tree item and note that the
   second line of controls that appears for sequential fits.
@@ -2644 +2669 @@
 
    <P></P>
-  <p class=MsoListParagraphCxSpMiddle>
+</OL>
+  <p class=MsoListParagraphCxSpMiddle style='PADDING-LEFT:0.25in'>
   <I>Note:
   Refinement of phase
@@ -2651 +2677 @@
   As of version 5038 of GSAS-II three modes were added for constraints
   in sequential refinements.
-  <UL style='PADDING-LEFT:0.75in'>
+  <UL style='PADDING-LEFT:1.0in'>
     <LI>In </I>"Ignore unless hist=*"<I> mode (which was
   the only mode prior to this version), any constraints with a
@@ -2667 +2693 @@
     </UL>
     </I>
-</OL>
   
 <h3>2. Perform the refinement.</h3>

trunk/GSASIIdataGUI.py

@@ -5610 +5610 @@
             else:
                 l = str(len(allwarnings)) + ' histograms'
-            msg = 'There were changes to constraints needed in {}. See console output or visit Constraints data tree item for more details. Continue with refinement?'.format(l)
-            dlg = wx.MessageDialog(self,msg,caption='Constraint changes',style=wx.YES_NO)
+            msg = 'There were constraint warnings generated in {}. See console output or visit the Constraints data tree item for more details. Continue with refinement?'.format(l)
+            dlg = wx.MessageDialog(self,msg,caption='Constraint warnings',style=wx.YES_NO)
             dlg.CenterOnParent()
             result = wx.ID_NO