diff --git a/src/graphics/arrows.c b/src/graphics/arrows.c
index 754860f..9933c65 100644
--- a/src/graphics/arrows.c
+++ b/src/graphics/arrows.c
@@ -135,18 +135,30 @@ int write_one_arrow_vertex (int offset_vertex,
     GLfloat arrow_tip_padding = (1 / max) / 10;
 
     switch(site){
-    case EAST:   case WEST:
-        graphics_write_vertex (vx + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding, vy, vz);
+    case EAST:
+        graphics_write_vertex (vx + (site % 2 - 1) * (1 / max) - (site % 2 - 1) * arrow_tip_padding, vy, vz);
         graphics_write_color (1.0f, 0.0f, 0.0f);
         break;
-    case ZENITH: case NADIR:
-        graphics_write_vertex (vx, vy + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding, vz);
+    case WEST:
+        graphics_write_vertex (vx + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding, vy, vz);
+        graphics_write_color (0.0f, 1.0f, 1.0f);
+        break;
+    case ZENITH:
+        graphics_write_vertex (vx, vy + (site % 2 - 1) * (1 / max) - (site % 2 - 1) * arrow_tip_padding, vz);
         graphics_write_color(0.0f, 1.0f, 0.0f);
         break;
-    case SOUTH:  case NORTH:
-        graphics_write_vertex (vx, vy, vz + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding);
+    case NADIR:
+        graphics_write_vertex (vx, vy + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding, vz);
+        graphics_write_color(1.0f, 0.0f, 1.0f);
+        break;
+    case SOUTH:
+        graphics_write_vertex (vx, vy, vz + (site % 2 - 1) * (1 / max) - (site % 2 - 1) * arrow_tip_padding);
         graphics_write_color(0.0f, 0.0f, 1.0f);
         break;
+    case NORTH:
+        graphics_write_vertex (vx, vy, vz + (site % 2) * (1 / max) - (site % 2) * arrow_tip_padding);
+        graphics_write_color(1.0f, 1.0f, 0.0f);
+        break;
     default: break;
     }
 
diff --git a/src/graphics/graphics.c b/src/graphics/graphics.c
index 49150e8..f317cc4 100644
--- a/src/graphics/graphics.c
+++ b/src/graphics/graphics.c
@@ -677,25 +677,25 @@ void  __attribute__((optimize("no-unroll-loops"))) main_test_graphics (void)
     void srand(unsigned int seed);  //    printf ("Valeur max : %d\n", RAND_MAX);   min + rand() % (max+1 - min);
 
     int arbitrary = 8;
-    int space_X = 1 + rand() % arbitrary,
-        space_Y = 1 + rand() % arbitrary,
-        space_Z = 1 + rand() % arbitrary;
+    int space_X = 6,//1 + rand() % arbitrary,
+        space_Y = 1,// + rand() % arbitrary,
+        space_Z = 1;// + rand() % arbitrary;
     int density_max = space_X * space_Y * space_Z;
     int max = fmax(space_X, space_Y); max = fmax(max, space_Z);
 
     int show_space_design = 1, print_arrows_data = 1;
 
     int load = 0, site = 0, x = 0, y = 0, z = 0;
-    int specif_arrows_nb = rand() % density_max / 3;
+    int specif_arrows_nb = 6;//rand() % density_max / 3;
     int arrows_nb = 0;
 
     while (arrows_nb < specif_arrows_nb){
         arrows_nb = set_arrow (arrows, arrows_nb,
                                rand() % arbitrary,  //    load / weight
-                               rand() % 6,          //    site,
-                               rand() % space_X,    //    x
-                               rand() % space_Y,    //    y
-                               rand() % space_Z);   //    z
+                               arrows_nb,//rand() % 6,          //    site,
+                               arrows_nb,//rand() % space_X,    //    x
+                               0,//rand() % space_Y,    //    y
+                               0);//rand() % space_Z);   //    z
     }
 
     print_user_choices(arrows, arrows_nb, space_X, space_Y, space_Z, print_arrows_data, show_space_design);