byshev_xs[min_i]), client_y);
        chebyshev_context.strokeStyle="#AA3311";
        chebyshev_context.stroke();
        chebyshev_context.closePath();
        chebyshev_context.setLineDash([]);
    }
}


// spline
var spline_xs = [-0.5, 0.5, 4.0, 3.0, 8.5, 7.5];
var spline_ys = [ 2.0, 1.0, 3.0, 4.0, 5.0, 6.0];
var spline_n = 6;
var spline_i = 0;

function init_spline(){
    spline = document.getElementById("spline");
    var canvas_rect = spline.getBoundingClientRect();
    spline_draw(0, 0, false);

   