diff --git a/src/graphics/arrows.c b/src/graphics/arrows.c
index 5ad6c0d..0a8042e 100644
--- a/src/graphics/arrows.c
+++ b/src/graphics/arrows.c
@@ -37,8 +37,6 @@ int write_one_arrow_vertex (int space_X_int, int space_Y_int, int space_Z_int,
      int weight, int site, int arrow_x, int arrow_y, int arrow_z, int print)
 {
 
-    printf("In write_one_arrow_vertex()  site = %d\n", site);
-
     float max = fmax(space_X_int, space_Y_int);
           max = fmax(max, space_Z_int);
 
diff --git a/src/graphics/graphics.c b/src/graphics/graphics.c
index 6666a06..30d5187 100644
--- a/src/graphics/graphics.c
+++ b/src/graphics/graphics.c
@@ -694,7 +694,7 @@ static inline int set_arrow (struct arrow_t *arrows_ptr, int arrows_nb, int spac
     int address = -1, current_weight = -1;
 
     if (console) printf("in set_arrow (begin)   arrows_nb = %d    requested site: %d    >   ", arrows_nb, site);
-    if (console) for (int i = 0; i < arrows_nb; i++) {printf(" [%d] = %d    ", i, arrows_ptr[i].site); if (site       ==  arrows_ptr[i].site) break;}
+    /* if (console) for (int i = 0; i < arrows_nb; i++) {printf(" [%d] = %d    ", i, arrows_ptr[i].site); if (site ==  arrows_ptr[i].site) break;} */
 
     for (int i = 0; i < arrows_nb; i++)
         if ((site       ==  arrows_ptr[i].site)
@@ -756,13 +756,13 @@ void main_test_graphics (void)
 
 
     srand(time(NULL)); int rand(void); void srand(unsigned int seed);
-    int randomize = 5, console = 0, arrows_nb = 0, space_X = 1, space_Y = 1, space_Z = 1;
+    int randomize = 60, console = 0, arrows_nb = 0, space_X = 1, space_Y = 1, space_Z = 1;
     if (randomize) {
         space_X = 1 + rand() % randomize;
         space_Y = 1 + rand() % randomize;
         space_Z = 1 + rand() % randomize;
     }
-    int density_max = space_X * space_Y * space_Z, specified_arrows_nb = rand() % density_max;
+    int density_max = space_X * space_Y * space_Z, specified_arrows_nb = density_max;
     int max = fmax(space_X, space_Y); max = fmax(max, space_Z);
 
 
@@ -790,7 +790,10 @@ void main_test_graphics (void)
     /*------------------------------------------------------------------------*/
 
 
+    printf("specified_arrows_nb: %d\n", specified_arrows_nb);
+
     if (randomize) for (int i = 0; i < specified_arrows_nb; i++)
+        {
         arrows_nb = set_arrow (arrows_ptr, arrows_nb, space_X, space_Y, space_Z,
                                1,                   //    load
                                rand() % 6,          //    site
@@ -798,11 +801,15 @@ void main_test_graphics (void)
                                rand() % space_Y,    //    y
                                rand() % space_Z,    //    z
                                console);
+            if (i > 0 && i % 1000 == 0) printf("|");
+            if (i > 0 && i % 100000 == 0) printf("\n");
+        }
     else for (int i = 0; i < 6; i++)
         arrows_nb = set_arrow (arrows_ptr, arrows_nb, 1, 1, 1, 1, i, 0, 0, 0, 0);
     int max_arrows_nb = arrows_nb;
+    printf("\nend initial arrows drawing\n");
 
-    if (randomize) for (int i = 0; i < specified_arrows_nb * 6; i++)
+    if (randomize) for (int i = 0; i < 6; i++)
         arrows_nb = set_arrow (arrows_ptr, arrows_nb, space_X, space_Y, space_Z,
                                rand() % 1,          //    load
                                rand() % 6,          //    site
@@ -811,9 +818,19 @@ void main_test_graphics (void)
                                rand() % space_Z,    //    z
                                console);
     else for (int i = 0; i < 6; i++)
-        arrows_nb = set_arrow (arrows_ptr, arrows_nb, 1, 1, 1, 0, i, 0, 0, 0, 1);
+        arrows_nb = set_arrow (arrows_ptr, arrows_nb, 1, 1, 1, 0, i, 0, 0, 0, 0);
 
-    if (randomize) print_user_choices(arrows_ptr, max_arrows_nb, arrows_nb, space_X, space_Y, space_Z, 1, 0);
+    int angle = 9;
+    if (space_X > angle && space_Y > angle && space_Z > angle) for (int i = 0; i < angle; i++)
+        for (int u = 0; u < angle; u++) for (int v = 0; v < angle; v++) for (int w = 0; w < angle; w++)
+            if (u + v + w < angle * 3)
+                arrows_nb = set_arrow (arrows_ptr, arrows_nb, 1, 1, 1, 0, i, u, v, w, 0);
+
+     if (space_X > angle && space_Y > angle && space_Z > angle)
+        printf("+ effacement des flèches dans l'angle-origine\
+  <=>  contrôle graphique de la fonction erase_arrow()\n");
+
+    if (randomize) print_user_choices(arrows_ptr, max_arrows_nb, arrows_nb, space_X, space_Y, space_Z, 0, 0);