diff --git a/dlib/gui_widgets/base_widgets.cpp b/dlib/gui_widgets/base_widgets.cpp
index 898692e43..4e4b3c7d1 100644
--- a/dlib/gui_widgets/base_widgets.cpp
+++ b/dlib/gui_widgets/base_widgets.cpp
@@ -2071,9 +2071,9 @@ namespace dlib
         parent.invalidate_rectangle(rect+old);
 
         const double old_scale = scale;
-        const vector<double> old_gr_orig(gr_orig);
+        const vector<double,2> old_gr_orig(gr_orig);
         scale = min_scale;
-        gr_orig = vector<double>(0,0,0);
+        gr_orig = vector<double,2>(0,0);
         lr_point = gui_to_graph_space(point(display_rect_.right(),display_rect_.bottom()));
         scale = old_scale;
 
@@ -2148,24 +2148,22 @@ namespace dlib
 
     point zoomable_region::
     graph_to_gui_space (
-        const vector<double>& p
+        const vector<double,2>& p
     ) const
     {
         const point rect_corner(display_rect_.left(), display_rect_.top());
-        const dlib::vector<double> v(p);
-        return (v - gr_orig)*scale + rect_corner;
+        return (p - gr_orig)*scale + rect_corner;
     }
 
 // ----------------------------------------------------------------------------------------
 
-    vector<double> zoomable_region::
+    vector<double,2> zoomable_region::
     gui_to_graph_space (
         const point& p
     ) const
     {
         const point rect_corner(display_rect_.left(), display_rect_.top());
-        const dlib::vector<double> v(p - rect_corner);
-        return v/scale + gr_orig;
+        return (p - rect_corner)/scale + gr_orig;
     }
 
 // ----------------------------------------------------------------------------------------
@@ -2217,7 +2215,7 @@ namespace dlib
 
     void zoomable_region::
     center_display_at_graph_point (
-        const vector<double>& p
+        const vector<double,2>& p
     )
     {
         // find the point in the center of the graph area
@@ -2363,11 +2361,11 @@ namespace dlib
     void zoomable_region::
     adjust_origin (
         const point& gui_p,
-        const vector<double>& graph_p
+        const vector<double,2>& graph_p
     )
     {
         const point rect_corner(display_rect_.left(), display_rect_.top());
-        const dlib::vector<double> v(gui_p - rect_corner);
+        const dlib::vector<double,2> v(gui_p - rect_corner);
         gr_orig = graph_p - v/scale;
 
 
@@ -2380,8 +2378,8 @@ namespace dlib
         // make sure the lower right corner of the display_rect_ doesn't map to a point beyond lr_point
         point lr_rect_corner(display_rect_.right(), display_rect_.bottom());
         point p = graph_to_gui_space(lr_point);
-        vector<double> lr_rect_corner_graph_space(gui_to_graph_space(lr_rect_corner));
-        vector<double> delta(lr_point - lr_rect_corner_graph_space);
+        vector<double,2> lr_rect_corner_graph_space(gui_to_graph_space(lr_rect_corner));
+        vector<double,2> delta(lr_point - lr_rect_corner_graph_space);
         if (lr_rect_corner.x() > p.x())
         {
             gr_orig.x() += delta.x();
@@ -2393,7 +2391,7 @@ namespace dlib
         }
 
 
-        const vector<double> ul_rect_corner_graph_space(gui_to_graph_space(rect_corner));
+        const vector<double,2> ul_rect_corner_graph_space(gui_to_graph_space(rect_corner));
         lr_rect_corner_graph_space = gui_to_graph_space(lr_rect_corner);
         // now adjust the scroll bars
 
diff --git a/dlib/gui_widgets/base_widgets.h b/dlib/gui_widgets/base_widgets.h
index de9531ce9..1109780cd 100644
--- a/dlib/gui_widgets/base_widgets.h
+++ b/dlib/gui_widgets/base_widgets.h
@@ -2155,10 +2155,10 @@ namespace dlib
     protected:
 
         point graph_to_gui_space (
-            const vector<double>& p
+            const vector<double,2>& p
         ) const;
 
-        vector<double> gui_to_graph_space (
+        vector<double,2> gui_to_graph_space (
             const point& p
         ) const;
 
@@ -2176,7 +2176,7 @@ namespace dlib
         );
 
         void center_display_at_graph_point (
-            const vector<double>& p
+            const vector<double,2>& p
         );
 
     // ----------- event handlers ---------------
@@ -2227,7 +2227,7 @@ namespace dlib
 
         void adjust_origin (
             const point& gui_p,
-            const vector<double>& graph_p
+            const vector<double,2>& graph_p
         );
         /*!
             ensures
@@ -2237,8 +2237,8 @@ namespace dlib
         !*/
 
 
-        vector<double> gr_orig; // point in graph space such that it's gui space point is the upper left of display_rect_
-        vector<double> lr_point; // point in graph space such that it is at the lower right corner of the screen at max zoom
+        vector<double,2> gr_orig; // point in graph space such that it's gui space point is the upper left of display_rect_
+        vector<double,2> lr_point; // point in graph space such that it is at the lower right corner of the screen at max zoom
 
         mutable std::ostringstream sout;
 
@@ -2249,7 +2249,7 @@ namespace dlib
         rectangle display_rect_;
 
         bool mouse_drag_screen;  // true if the user is dragging the white background area
-        vector<double> drag_screen_point; // the starting point the mouse was at in graph space for the background area drag
+        vector<double,2> drag_screen_point; // the starting point the mouse was at in graph space for the background area drag
 
         scroll_bar vsb;
         scroll_bar hsb;
diff --git a/dlib/gui_widgets/base_widgets_abstract.h b/dlib/gui_widgets/base_widgets_abstract.h
index 0f8dfa292..569f68b2b 100644
--- a/dlib/gui_widgets/base_widgets_abstract.h
+++ b/dlib/gui_widgets/base_widgets_abstract.h
@@ -1599,9 +1599,6 @@ namespace dlib
                 determined automatically from the size of this object's on screen 
                 rectangle and the value of min_zoom_scale() which determines how far 
                 out you can zoom.
-
-                Also note that while dlib::vector<double> is used to represent graph points
-                the z field is always ignored by this object.
         */
 
     public:
@@ -1719,7 +1716,7 @@ namespace dlib
         !*/
 
         point graph_to_gui_space (
-            const vector<double>& graph_point
+            const vector<double,2>& graph_point
         ) const;
         /*!
             requires
@@ -1729,7 +1726,7 @@ namespace dlib
                   to the given point in Cartesian graph space
         !*/
 
-        vector<double> gui_to_graph_space (
+        vector<double,2> gui_to_graph_space (
             const point& pixel_point
         ) const;
         /*!
@@ -1740,7 +1737,7 @@ namespace dlib
                   pixel location
         !*/
 
-        vector<double> max_graph_point (
+        vector<double,2> max_graph_point (
         ) const;
         /*!
             requires
@@ -1782,7 +1779,7 @@ namespace dlib
         !*/
 
         void center_display_at_graph_point (
-            const vector<double>& graph_point
+            const vector<double,2>& graph_point
         );
         /*!
             requires
diff --git a/dlib/gui_widgets/widgets.h b/dlib/gui_widgets/widgets.h
index a1660b560..2c90e0aee 100644
--- a/dlib/gui_widgets/widgets.h
+++ b/dlib/gui_widgets/widgets.h
@@ -2091,11 +2091,11 @@ namespace dlib
                 }
 
                 bool click_hit_node = false;
-                dlib::vector<double> p(gui_to_graph_space(point(x,y)));
+                dlib::vector<double,2> p(gui_to_graph_space(point(x,y)));
                 // check if this click is on an existing node
                 for (unsigned long i = 0; i < graph_.number_of_nodes(); ++i)
                 {
-                    dlib::vector<double> n(graph_.node(i).data.p);
+                    dlib::vector<double,2> n(graph_.node(i).data.p);
                     if ((p-n).length() < radius)
                     {
                         click_hit_node = true;
@@ -2135,10 +2135,10 @@ namespace dlib
                 {
                     for (unsigned long n = 0; n < graph_.number_of_nodes() && edge_selected == false; ++n)
                     {
-                        const dlib::vector<double> parent_center(graph_to_gui_space(graph_.node(n).data.p));
+                        const dlib::vector<double,2> parent_center(graph_to_gui_space(graph_.node(n).data.p));
                         for (unsigned long e = 0; e < graph_.node(n).number_of_children() && edge_selected == false; ++e)
                         {
-                            const dlib::vector<double> child_center(graph_to_gui_space(graph_.node(n).child(e).data.p));
+                            const dlib::vector<double,2> child_center(graph_to_gui_space(graph_.node(n).child(e).data.p));
 
                             rectangle area;
                             area += parent_center;
@@ -2149,7 +2149,7 @@ namespace dlib
                                 p = point(x,y);
                                 const dlib::vector<double> z(0,0,1);
                                 // find the distance from the line between the two nodes
-                                const dlib::vector<double> perpendicular(z.cross(parent_center-child_center).normalize());
+                                const dlib::vector<double,2> perpendicular(z.cross(parent_center-child_center).normalize());
                                 double distance = std::abs((child_center-p).dot(perpendicular));
                                 if (distance < 8)
                                 {
@@ -2197,11 +2197,11 @@ namespace dlib
                 (state & base_window::SHIFT) && 
                 selected_node != graph_.number_of_nodes() )
             {
-                dlib::vector<double> p(gui_to_graph_space(point(x,y)));
+                dlib::vector<double,2> p(gui_to_graph_space(point(x,y)));
                 // check if this click is on an existing node
                 for (unsigned long i = 0; i < graph_.number_of_nodes(); ++i)
                 {
-                    dlib::vector<double> n(graph_.node(i).data.p);
+                    dlib::vector<double,2> n(graph_.node(i).data.p);
                     if ((p-n).length() < radius)
                     {
                         // add the edge if it doesn't already exist and isn't an edge back to 
@@ -2272,7 +2272,7 @@ namespace dlib
                         color.red = 255;
                         // we need to be careful when drawing this line to not draw it over the node dots since it 
                         // has a different color from them and would look weird
-                        dlib::vector<double> v(p-center);
+                        dlib::vector<double,2> v(p-center);
                         v = v.normalize()*rad;
                         draw_line(c,center+v,p-v ,color, area);
                     }
@@ -2285,11 +2285,11 @@ namespace dlib
                     // draw the triangle pointing to this node
                     if (area.intersect(circle_area).is_empty() == false)
                     {
-                        dlib::vector<double> v(p-center);
+                        dlib::vector<double,2> v(p-center);
                         v = v.normalize();
 
-                        dlib::vector<double> cross = z.cross(v).normalize();
-                        dlib::vector<double> r(center + v*rad);
+                        dlib::vector<double,2> cross = z.cross(v).normalize();
+                        dlib::vector<double,2> r(center + v*rad);
                         for (double i = 0; i < 8*zoom_scale(); i += 0.1)
                             draw_line(c,(r+v*i)+cross*i, (r+v*i)-cross*i,color,area);
                     }