From 72301b3d5c3a91ff2e7fc6eedcad7bce8e647efa Mon Sep 17 00:00:00 2001
From: Jaron Kent-Dobias <jaron@kent-dobias.com>
Date: Thu, 19 Jul 2018 18:22:15 -0400
Subject: efficient computation of the smallest fourier mode by doing a
 magnetization-style update anytime a bond with the external field changes

---
 lib/vector.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'lib/vector.h')

diff --git a/lib/vector.h b/lib/vector.h
index 2099d28..a1084e2 100644
--- a/lib/vector.h
+++ b/lib/vector.h
@@ -36,6 +36,20 @@ void add (vector_t <q, T> *v1, vector_t <q, T> v2) {
   }
 }
 
+template <q_t q, class T>
+void scalar_add (vector_t <q, T> *v1, T a, vector_t <q, T> v2) {
+  for (q_t i = 0; i < q; i++) {
+    v1->x[i] += a * v2.x[i];
+  }
+}
+
+template <q_t q, class T>
+void scalar_subtract (vector_t <q, T> *v1, T a, vector_t <q, T> v2) {
+  for (q_t i = 0; i < q; i++) {
+    v1->x[i] -= a * v2.x[i];
+  }
+}
+
 template <q_t q, class T>
 void subtract (vector_t <q, T> *v1, vector_t <q, T> v2) {
   for (q_t i = 0; i < q; i++) {
@@ -43,6 +57,16 @@ void subtract (vector_t <q, T> *v1, vector_t <q, T> v2) {
   }
 }
 
+template <q_t q, class T>
+T norm_squared (vector_t <q, T> v) {
+  T tmp = 0;
+  for (q_t i = 0; i < q; i++) {
+    tmp += v.x[i] * v.x[i];
+  }
+
+  return tmp;
+}
+
 template <q_t q, class T>
 vector_t <q, T> scalar_multiple(v_t a, vector_t <q, T> v) {
   vector_t <q, T> multiple;
-- 
cgit v1.2.3-70-g09d2