From 5f1f3dd9bea9ba015656aa0ccd047e04588fd67a Mon Sep 17 00:00:00 2001 From: Dennis Mikkelson <mikkelsond@uwstout.edu> Date: Sun, 30 Dec 2012 21:05:53 -0600 Subject: [PATCH] RE 6331 Adding WIKI documentation refs #6331 --- .../MDEvents/src/IntegrateEllipsoids.cpp | 47 ++++++++++++++++++- 1 file changed, 46 insertions(+), 1 deletion(-) diff --git a/Code/Mantid/Framework/MDEvents/src/IntegrateEllipsoids.cpp b/Code/Mantid/Framework/MDEvents/src/IntegrateEllipsoids.cpp index 4ce7d095926..d9f567b6aca 100644 --- a/Code/Mantid/Framework/MDEvents/src/IntegrateEllipsoids.cpp +++ b/Code/Mantid/Framework/MDEvents/src/IntegrateEllipsoids.cpp @@ -1,5 +1,50 @@ /*WIKI* -TODO: Enter a full wiki-markup description of your algorithm here. You can then use the Build/wiki_maker.py script to generate your full wiki page. + * This algorithm will integrate a list of indexed single-crystal diffraction peaks from a + * PeaksWorkspace, using events from an EventWorkspace. The indexed peaks are first + * used to determine a UB matrix. The inverse of that UB matrix is then used to collect + * lists of events that are close to peaks in reciprocal space. An event will be added + * to the list of events for a peak provided that the fractional h,k,l value of that + * event (obtained by applying UB-inverse to the Q-vector) is closer to the h,k,l of that + * peak, than to the h,k,l of any other peak AND the Q-vector for that event is within + * the specified radius of the Q-vector for that peak. + * + * When the lists of events near the peaks have been built, the three principal axes of + * the "cloud" of events near each peak are found, and the standard deviations of the + * projections of the events on each of the three principal axes are calculated. The + * principal axes and standard deviations for the events around a peak in the directions + * of the principal axes are used to determine an ellipsoidal region for the peak and an + * ellipsoidal shell region for the background. The number of events in the peak + * ellipsoid and background ellipsoidal shell are counted and used to determine the net + * integrated intensity of the peak. + * + * The ellipsoidal regions used for the peak and background can be obtained in two ways. + * First, the user may specify the size of the peak ellipsoid and the inner and outer + * size of the background ellipsoid. If these are specified, the values will be used + * for half the length of the major axis of an ellipsoid centered on the peak. The + * major axis is in the direction of the principal axis for which the standard deviation + * in that direction is largest. The other two axes for the ellipsoid are in the + * direction of the other two principal axes and are scaled relative to the major axes + * in proportion to their standard deviations. For example of the standard deviations + * in the direction of the other two princial axes are .8 and .7 times the standard + * deviation in the direction of the major axis, then the ellipse will extend only .8 + * and .7 times as far in the direction of those axes, as in the direction of the major + * axis. Overall, the user specified sizes for the PeakSize, BackgroundInnerSize and + * BackgroundOuterSize are similar to the PeakRadius, BackgroundInnerRadius and + * BackgrounOuterRadius for the IntegratePeaksMD algorithm. The difference is that + * the regions used in this algorithm are not spherical, but are ellipsoidal with axis + * directions obtained from the principal axes of the events near a peak and the + * ellipsoid shape (relative axis lengths) determined by the standard deviations in + * the directions of the principal axes. + * + * Second, if the user does not specifiy the size of the peak and background ellipsoids, + * then the three axes of the peak ellipsoid are again set to the principal axes of the + * nearby events and their axis lengths are set to cover a range of plus or minus + * three standard deviations in the axis directions. In this case, the background + * ellipsoidal shell is chosen to have the same volume as the peak ellipsoid and it's + * inner surface is the outer surface of the peak ellipsoid. The outer surface of the + * background ellipsoidal shell is an ellipsoidal surface with the same relative axis + * lengths as the inner surface. + * *WIKI*/ #include <iostream> -- GitLab