Changeset 490f790 in sasview

Timestamp:

Sep 28, 2018 7:20:48 AM (6 years ago)

Author:

smk78

Branches:

master, magnetic_scatt, release-4.2.2, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, unittest-saveload

Children:

2ae8579

Parents:

acdf0d1

Message:

Tweaks to corfunc_help.rst

File:

• src/sas/sasgui/perspectives/corfunc/media/corfunc_help.rst (modified) (9 diffs)

src/sas/sasgui/perspectives/corfunc/media/corfunc_help.rst

@@ -33 +33 @@
 Both analyses are performed in 3 stages:
 
-*  Extrapolation of the scattering curve to :math:`Q = 0` and toward 
-   :math:`Q = \infty`
+*  Extrapolation of the scattering curve to :math:`q = 0` and toward 
+   :math:`q = \infty`
 *  Smoothed merging of the two extrapolations into the original data
 *  Fourier / Hilbert Transform of the smoothed data to give the correlation
@@ -47 +47 @@
 -------------
 
-To :math:`Q = 0`
+To :math:`q = 0`
 ................
 
@@ -67 +67 @@
 the impact on any extrapolated parameters will be least significant.
 
-To :math:`Q = \infty`
+To :math:`q = \infty`
 .....................
 
@@ -145 +145 @@
         - do they smoothly curve onto the ordinate at x = 0? (if not check the value 
           of :math:`\sigma` is sensible)
-        - are there ripples at x values corresponding to (2 :math:`pi` over) the two 
+        - are there ripples at x values corresponding to (2 :math:`\pi` over) the two 
           q values at which the extrapolated and experimental data are merged?
-        - are there any artefacts at x values corresponding to 2 :math:`pi` / q\ :sub:`max` in 
+        - are there any artefacts at x values corresponding to 2 :math:`\pi` / q\ :sub:`max` in 
           the experimental data? 
         - and lastly, do the significant features/peaks in the correlation functions 
@@ -158 +158 @@
     -q^{4} I(q)
 
-The IDF is proportional to the second derivative of Γ\ :sub:`1`\ (x).
+The IDF is proportional to the second derivative of Γ\ :sub:`1`\ (x) and represents a 
+superposition of thickness distributions from all the contributing lamellae. 
 
 Hilbert
@@ -192 +193 @@
 *   Local Crystallinity :math:`= L_c/L_p`
 
+.. warning:: If the sample does not possess lamellar morphology then "Compute 
+    Parameters" will return garbage!
+        
+
 Volume Fraction Profile
 .......................
@@ -213 +218 @@
 
 The reader is directed to the references for information on these parameters.
+
 
 References
@@ -263 +269 @@
 Once the Q ranges have been set, click the "Calculate Bg" button to determine the 
 background level. Alternatively, enter your own value into the box. If the box turns 
-yellow this indicates that background subtraction has created some negative intensities.
+yellow this indicates that background subtraction has created some negative intensities. 
+This may still be fine provided the peak intensity is very much greater than the 
+background level. The important point is that the extrapolated dataset must approach 
+zero at high-q.
 
 Now click the "Extrapolate" button to extrapolate the data. The graph window will update 
@@ -296 +305 @@
 
 .. note::
-    This help document was last changed by Steve King, 26Sep2017
+    This help document was last changed by Steve King, 28Sep2017