Merge pull request #71 from jnj16180340/bug_2d-quiver-plots-arent-showing-arrows

2d quiver plots have arrowheads

Author: jnj16180340

plotly/plotlyfig_aux/handlegraphics/updateQuiver.m

@@ -88,6 +88,47 @@
 
 %-------------------------------------------------------------------------%
 
+%-quiver barbs-%
+if isHG2()
+    % 'MaxHeadSize' scalar, matlab clips to 0.2 in r2014b
+    maxheadsize = quiver_data.MaxHeadSize;
+    % barb angular width, not supported by matlab
+    head_width = deg2rad(17.5);
+    for n = 1:length(xdata)
+        % length of arrow
+        l = norm([0.1*udata(n), 0.1*vdata(n)]);
+        
+        % angle of arrow
+        phi = atan2(vdata(n),udata(n));
+        
+        % make barb with specified angular width, length is prop. to arrow
+        barb = [...
+            [-maxheadsize*l*cos(head_width), maxheadsize*l*sin(head_width)]; ...
+            [0, 0]; ...
+            [-maxheadsize*l*cos(head_width), -maxheadsize*l*sin(head_width)]; ...
+            [nan, nan]; ...
+            ]';
+        
+        % affine matrix: rotate by arrow angle and translate to end of arrow
+        barb_transformation = affine2d([...
+            [cos(phi), sin(phi), 0]; ...
+            [-sin(phi), cos(phi), 0]; ...
+            [xdata(n) + 0.1*udata(n), ydata(n) + 0.1*vdata(n), 1];
+            ]);
+        
+        % place barb at end of arrow
+        barb = transformPointsForward(barb_transformation, barb')';
+        
+        % add barb to plot data, inserting is optimized in matlab >2010
+        for col = 1:4
+            obj.data{quiverIndex}.x(end+1) = barb(1,col); % point 1
+            obj.data{quiverIndex}.y(end+1) = barb(2,col);
+        end
+    end
+end
+
+%-------------------------------------------------------------------------%
+
 %-scatter showlegend-%
 leg = get(quiver_data.Annotation);
 legInfo = get(leg.LegendInformation);