--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/+grid/old/triang_interp.m	Thu Sep 17 10:12:50 2015 +0200
@@ -0,0 +1,132 @@
+classdef triang_interp
+    properties
+        g1, g2 ,g3  % Curves encirling the tirangle in the positive direction.
+        A,B,C  % The corners of the triangle
+        Sa, Sb, Sc % Mappings from square with different sides collapsed
+    end
+
+    methods
+        function o = triang_interp(g1,g2,g3)
+            o.g1 = g1;
+            o.g2 = g2;
+            o.g3 = g3;
+            o.A = g1(0);
+            o.B = g2(0);
+            o.C = g3(0);
+            o.Sa = grid.triang_interp.square_to_triangle_interp(g2,g3,g1);
+            o.Sb = grid.triang_interp.square_to_triangle_interp(g3,g1,g2);
+            o.Sc = grid.triang_interp.square_to_triangle_interp(g1,g2,g3);
+        end
+
+
+        function show(o,N)
+            % Show the mapped meridians of the triangle.
+            % Might be used for the barycentric coordinates.
+            ma = @(t)o.Sa(1/2,1-t);
+            mb = @(t)o.Sb(1/2,1-t);
+            mc = @(t)o.Sc(1/2,1-t);
+
+            na = @(t)o.Sa(t,1/2);
+
+            ka = @(t)(o.g1(1-t)+o.g2(t))/2;
+
+            h = grid.plot_curve(ma);
+            h.Color = Color.blue;
+            h = grid.plot_curve(mb);
+            h.Color = Color.blue;
+            h = grid.plot_curve(mc);
+            h.Color = Color.blue;
+
+            h = grid.plot_curve(na);
+            h.Color = Color.red;
+
+            h = grid.plot_curve(ka);
+            h.Color = Color.red;
+
+            [a(1),a(2)] = ma(1/3);
+            [b(1),b(2)] = mb(1/3);
+            [c(1),c(2)] = mc(1/3);
+
+            d = ka(1-1/3);
+
+
+            grid.label_pt(a,b,c,d);
+
+
+            % t = linspace(0,1,N);
+            % for i = 1:N
+            %     sa = @(s)o.Sa(s,t(i));
+            %     sb = @(s)o.Sb(s,t(i));
+            %     sc = @(s)o.Sc(s,t(i));
+
+            %     h = grid.plot_curve(sa);
+            %     h.Color = Color.blue;
+            %     h = grid.plot_curve(sb);
+            %     h.Color = Color.blue;
+            %     h = grid.plot_curve(sc);
+            %     h.Color = Color.blue;
+            % end
+
+            h = grid.plot_curve(o.g1);
+            h.LineWidth = 2;
+            h.Color = Color.red;
+
+            h = grid.plot_curve(o.g2);
+            h.LineWidth = 2;
+            h.Color = Color.red;
+
+            h = grid.plot_curve(o.g3);
+            h.LineWidth = 2;
+            h.Color = Color.red;
+
+        end
+
+
+    end
+
+    methods(Static)
+        % Makes a mapping from the unit square to a triangle by collapsing
+        % one of the sides of the squares to a corner on the triangle
+        % The collapsed side is mapped to the corner oposite to g1.
+        % This is done such that for S(s,t), S(s,1) = g1(s)
+        function S = square_to_triangle_interp(g1,g2,g3)
+            corner = grid.line_segment(g3(0),g3(0));
+            S = grid.transfinite_interp(corner,g3,f(g1),f(g2))
+
+            % Function to flip a curve
+            function h = f(g)
+                h = @(t)g(1-t);
+            end
+        end
+    end
+
+end
+
+% % Return a mapping from u.v to x,y of the domain encircled by g1 g2 g3 in the the positive direction. created be using transfinite interpolation.
+% function S = triang_interp(g1,g2,g3)
+%     A = g1(0)
+%     B = g2(0)
+%     C = g3(0)
+
+%     function [x,y] = S_fun(u,v)
+%         w = sqrt((u-1)^2+v^2)/sqrt(2); % Parameter for g3
+%         v = v*(1-u-v)*g1(u) + u*(1-u-v)*g2(v) + u*v*g3(w) ...
+%             +(1-u)*(1-v)*A+u*(1-v)*B + (1-u)*v*C;
+%         x = v(1);
+%         y = v(2);
+%     end
+%     S = @S_fun;
+% end
+
+
+
+% function subsref(obj,S)
+%       if ~all(isnumeric(S.subs{:}))
+%         error('Only supports calling object with number')
+%       end
+%       if numel(S.subs{:}) > 1
+%         disp('You''ve called the object with more than one argument');
+%       else
+%         disp(['You called the object with argument = ',num2str(S.subs{:})]);
+%       end
+%     end
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