Ugly drawing of MS asp.net radar chart
WPF coordinates refer to the center of the pixel, not the corners, so try adding 0.5 to all your coordinates. To show this is the case consider the following xaml:
<Canvas><Line X1="50" Y1="50" X2="100" Y2="50" Stroke="Black" StrokeThickness="1" /><Line X1="50" Y1="50" X2="50" Y2="100" Stroke="Black" StrokeThickness="1" /><Line X1="50" Y1="50" X2="100" Y2="100" Stroke="Black" StrokeThickness="1" /></Canvas>Here it is rendered normally and then with a 0.5 pixel offset applied to each coordinate:
