1 files changed, 3 insertions, 18 deletions
diff --git a/lib/correlation.h b/lib/correlation.h
index 5722aab..b3b7d86 100644
--- a/lib/correlation.h
+++ b/lib/correlation.h
@@ -7,29 +7,14 @@
 #include <fftw3.h>
 
 template <class R_t, class X_t>
-double correlation_length(const state_t <R_t, X_t> *s) {
-  double *data = (double *)fftw_malloc(s->nv * sizeof(double));
-  int rank = s->D;
-  int *n = (int *)malloc(rank * sizeof(int));
-  fftw_r2r_kind *kind = (fftw_r2r_kind *)malloc(rank * sizeof(fftw_r2r_kind));
-  for (D_t i = 0; i < rank; i++) {
-    n[i] = s->L;
-    kind[i] = FFTW_R2HC;
-  }
-  fftw_plan plan = fftw_plan_r2r(rank, n, data, data, kind, 0);
-
+double correlation_length(const state_t <R_t, X_t> *s, fftw_plan plan, double *in, double *out) {
   for (v_t i = 0; i < s->nv; i++) {
-    data[i] = correlation_component(s->spins[i]);
+    in[i] = correlation_component(s->spins[i]);
   }
 
   fftw_execute(plan);
 
-  double length = pow(data[0], 2);
-
-  fftw_destroy_plan(plan);
-  fftw_free(data);
-  free(n);
-  free(kind);
+  double length = pow(out[0], 2);
 
   return length;
 }