1 files changed, 23 insertions, 0 deletions
diff --git a/examples/include/correlation.hpp b/examples/include/correlation.hpp
new file mode 100644
index 0000000..042cff3
--- /dev/null
+++ b/examples/include/correlation.hpp
@@ -0,0 +1,23 @@
+
+#pragma once
+
+#include <wolff/types.h>
+#include <wolff/state.hpp>
+
+#include <fftw3.h>
+
+template <class R_t, class X_t>
+double correlation_length(const state_t <R_t, X_t>& s) {
+  double total = 0;
+
+#ifdef DIMENSION
+  for (D_t j = 0; j < DIMENSION; j++) {
+#else
+  for (D_t j = 0; j < s.D; j++) {
+#endif
+    total += norm_squared(s.ReF[j]) + norm_squared(s.ImF[j]);
+  }
+
+  return total / s.D;
+}
+