OK In progress...

src/Axis.vala

@@ -143,5 +143,10 @@ namespace CairoChart {
 				}
 			}
 		}
+
+		public virtual void unzoom () {
+			zoom_min = min;
+			zoom_max = max;
+		}
 	}
 }

src/Chart.vala

@@ -254,17 +254,7 @@ namespace CairoChart {
 		 * Zooms out the ``Chart``.
 		 */
 		public virtual void zoom_out () {
-			foreach (var s in series) {
-				s.zoom_show = true;
-				s.axis_x.zoom_min = s.axis_x.min;
-				s.axis_x.zoom_max = s.axis_x.max;
-				s.axis_y.zoom_min = s.axis_y.min;
-				s.axis_y.zoom_max = s.axis_y.max;
-				s.place.zoom_x_min = s.place.x_min;
-				s.place.zoom_x_max = s.place.x_max;
-				s.place.zoom_y_min = s.place.y_min;
-				s.place.zoom_y_max = s.place.y_max;
-			}
+			foreach (var s in series) s.unzoom();
 			zoom = Cairo.Rectangle() { x = 0, y = 0, width = 1, height = 1 };
 			zoom_1st_idx = 0;
 		}

src/Place.vala

@@ -48,5 +48,12 @@ namespace CairoChart {
 			zoom_y_min = y_min;
 			zoom_y_max = y_max;
 		}
+
+		public virtual void unzoom () {
+			zoom_x_min = x_min;
+			zoom_x_max = x_max;
+			zoom_y_min = y_min;
+			zoom_y_max = y_max;
+		}
 	}
 }

src/Series.vala

@@ -567,5 +567,12 @@ namespace CairoChart {
 		public virtual Point128 get_real_point (Point p) {
 			return Point128 (get_real_x(p.x), get_real_y(p.y));
 		}
+
+		public virtual void unzoom () {
+				zoom_show = true;
+				axis_x.unzoom();
+				axis_y.unzoom();
+				place.unzoom();
+		}
 	}
 }