From 74817b0906b93cf10493165d06a452f413eae4dc Mon Sep 17 00:00:00 2001
From: Anthony Lim <anthony.lim@stfc.ac.uk>
Date: Tue, 6 Jun 2017 12:43:38 +0100
Subject: [PATCH] refs #19802 fixed documentation for dynamicKuboToyabe
---
.../src/Functions/DynamicKuboToyabe.cpp | 14 ++++++++++----
docs/source/fitfunctions/DynamicKuboToyabe.rst | 7 ++++++-
2 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/Framework/CurveFitting/src/Functions/DynamicKuboToyabe.cpp b/Framework/CurveFitting/src/Functions/DynamicKuboToyabe.cpp
index 14e55390b02..61c1d0c7137 100644
--- a/Framework/CurveFitting/src/Functions/DynamicKuboToyabe.cpp
+++ b/Framework/CurveFitting/src/Functions/DynamicKuboToyabe.cpp
@@ -128,23 +128,26 @@ double integral(double func(const double, const double, const double),
// f1: function to integrate
double f1(const double x, const double G, const double w0) {
+ // G = Delta in doc
+ // x = dummy time variable
return (exp(-G * G * x * x / 2) * sin(w0 * x));
}
// Static Zero Field Kubo Toyabe relaxation function
+// Also called Lorentzian Kubo-Toyabe
double ZFKT(const double x, const double G) {
-
+ // q = Delta^2 t^2 in doc
const double q = G * G * x * x;
return (0.3333333333 + 0.6666666667 * exp(-0.5 * q) * (1 - q));
}
// Static non-zero field Kubo Toyabe relaxation function
double HKT(const double x, const double G, const double F) {
-
+ // q = Delta^2 t^2 in doc
const double q = G * G * x * x;
// Muon gyromagnetic ratio * 2 * PI
const double gm = 2 * M_PI * PhysicalConstants::MuonGyromagneticRatio;
-
+ // w = omega_0 in doc
double w;
if (F > 2 * G) {
// Use F
@@ -153,7 +156,7 @@ double HKT(const double x, const double G, const double F) {
// Use G
w = gm * 2 * G;
}
-
+ // r = Delta^2/omega_0^2
const double r = G * G / w / w;
double ig;
@@ -169,8 +172,10 @@ double HKT(const double x, const double G, const double F) {
(1 - 2 * r * (1 - exp(-q / 2) * cos(w * x)) + 2 * r * r * w * ig);
if (F > 2 * G) {
+ // longitudinal Gaussian field
return ktb;
} else {
+ //
const double kz = ZFKT(x, G);
return kz + F / 2 / G * (ktb - kz);
}
@@ -223,6 +228,7 @@ double DynamicKuboToyabe::getDKT(double t, double G, double F, double v,
// Generate dynamic Kubo Toyabe
for (int k = 0; k < tsmax; k++) {
double y = gStat[k];
+ // do integration
for (int j = k - 1; j > 0; j--) {
y = y * (1 - hop) + hop * gDyn[k - j] * gStat[j];
}
diff --git a/docs/source/fitfunctions/DynamicKuboToyabe.rst b/docs/source/fitfunctions/DynamicKuboToyabe.rst
index 99181d2261b..29e0579654a 100644
--- a/docs/source/fitfunctions/DynamicKuboToyabe.rst
+++ b/docs/source/fitfunctions/DynamicKuboToyabe.rst
@@ -12,7 +12,7 @@ Description
Dynamic Kubo Toyabe fitting function for use by Muon scientists defined
by
-.. math:: G_z \left(t\right) = g_z\left(t\right) e^{-\nu t} + \nu \int_0^t g_z\left(\tau\right) e^{-\nu\tau} G_z\left(t-\tau\right) d\tau
+.. math:: G_z \left(t\right) = g_z\left(t\right) + \nu \int_0^t g_z\left(\tau\right) G_z\left(t-\tau\right) d\tau
where :math:`g_z\left(t\right)` is the static KT function, and :math:`\nu` the muon hopping rate.
@@ -31,6 +31,11 @@ small values will lead to long calculation times, while large values will produc
.. properties::
+References
+----------
+
+[1] `Hayano et al., PRB 20 (1979) 50 <https://journals.aps.org/prb/abstract/10.1103/PhysRevB.20.850>`_.
+
.. categories::
.. sourcelink::
--
GitLab