diff --git a/fftma_module/gen/lib_src/fftma2.c b/fftma_module/gen/lib_src/fftma2.c
index 341774b..9ead660 100644
--- a/fftma_module/gen/lib_src/fftma2.c
+++ b/fftma_module/gen/lib_src/fftma2.c
@@ -69,5 +69,30 @@ void FFTMA2(struct vario_mod variogram, struct grid_mod grid, int n[3], struct r
     printf("Running with covar and ireal\n");
     fourt(covar, ireal, n, NDIM, 1, 0, workr, worki, cores);
 
-    chunk_array_flush(covar);
+    /*organization of the input Gaussian white noise*/
+    solver = 0;
+    prebuild_gwn(grid, n, realin, realization, solver, cores, seed);
+
+    /*forward fourier transform of the GWN*/
+    printf("Running with realization and ireal\n");
+    fourt(realization, ireal, n, NDIM, 1, 0, workr, worki, cores);
+
+    /* build realization in spectral domain   */
+    build_real(n, NTOT, covar, realization, ireal, cores);
+
+    chunk_array_free(covar);
+    //remove("covar.txt");
+
+    /*backward fourier transform*/
+    printf("Running with realization and ireal\n");
+    fourt(realization, ireal, n, NDIM, 0, 1, workr, worki, cores);
+
+    chunk_array_free(ireal);
+    remove("ireal.txt");
+
+    free(workr);
+    free(worki);
+
+    /*output realization*/
+    clean_real(realin, n, grid, realization, realout, cores);
 }