Changeset 8a22b5b in sasview for src/sas/perspectives/pr/media/pr_help.rst

Timestamp:

Feb 19, 2015 11:20:54 AM (9 years ago)

Author:

smk78

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, costrafo411, magnetic_scatt, release-4.1.1, release-4.1.2, release-4.2.2, release_4.0.1, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, ticket885, unittest-saveload

Children:

0721c3d

Parents:

6271222

Message:

Proof read.

File:

• src/sas/perspectives/pr/media/pr_help.rst (modified) (2 diffs)

src/sas/perspectives/pr/media/pr_help.rst

@@ -5 +5 @@
 
 .. |pi| unicode:: U+03C0
+.. |bigphi| unicode:: U+03A6
+.. |bigsigma| unicode:: U+03A3
 .. |chi| unicode:: U+03C7
 
@@ -10 +12 @@
 ==========================
 
-The inversion approach is based on Moore, J. Appl. Cryst., (1980) 13, 168-175.
+Description
+-----------
 
-P(r) is set to be equal to an expansion of base functions of the type
-phi_n(r) = 2 * r * sin(|pi| * n * r / D_max).
+This tool calculates a real-space distance distribution function, *P(r)*, using 
+the inversion approach (Moore, 1908).
+
+*P(r)* is set to be equal to an expansion of base functions of the type
+
+  |bigphi|\_n(r) = 2.r.sin(|pi|\ .n.r/D_max)
 
 The coefficient of each base function in the expansion is found by performing 
-a least square fit with the following fit function:
+a least square fit with the following fit function
 
-|chi| ^2 = sum_i[ I_meas(q_i) - I_th(q_i) ]^2 / error^2 + Reg_term
+  |chi|\ :sup:`2` = |bigsigma|\ :sub:`i` [ I\ :sub:`meas`\ (Q\ :sub:`i`\ ) - I\ :sub:`th`\ (Q\ :sub:`i`\ ) ] :sup:`2` / (Error) :sup:`2` + Reg_term
 
-where I_meas(q) is the measured scattering intensity and I_th(q) is the 
-prediction from the Fourier transform of the P(r) expansion. 
+where I\ :sub:`meas`\ (Q) is the measured scattering intensity and 
+I\ :sub:`th`\ (Q) is the prediction from the Fourier transform of the *P(r)* 
+expansion. 
 
-The Reg_term term is a regularization term set to the second derivative 
-d^2 P(r) / dr^2 integrated over r. It is used to produce a smooth P(r) output.
+The *Reg_term* term is a regularization term set to the second derivative 
+d\ :sup:`2`\ *P(r)* / dr\ :sup:`2` integrated over *r*. It is used to produce a 
+smooth *P(r)* output.
 
-The following are user inputs:
+.. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
 
-*  Number of terms: the number of base functions in the P(r) expansion.
+How To
+------
+
+The user must enter
+
+*  *Number of terms*: the number of base functions in the P(r) expansion.
    
-*  Regularization constant: a multiplicative constant to set the size of
+*  *Regularization constant*: a multiplicative constant to set the size of
    the regularization term.
 
-*  Maximum distance: the maximum distance between any two points in the
+*  *Maximum distance*: the maximum distance between any two points in the
    system.
+
+.. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
+
+Reference
+---------
+
+P.B. Moore
+*J. Appl. Cryst.*, 13 (1980) 168-175
+
+.. ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
+
+.. note::  This help document was last changed by Steve King, 19Feb2015