] = spline_ys[i+2];

        A2[i+1] = [];
        for(var j = 0; j < 4-1; ++j)
            A2[i+1][j+1] = Math.pow(spline_xs[i+2], j) * (j+1);
        A2[i+1][0] = 0.0;
        B2[i+1] = (spline_ys[i+1+2] - spline_ys[i+2]) / (spline_xs[i+1+2] - spline_xs[i+2]);
    }
    X2 = solved_linear(A2, B2, 4);

    spline_context.beginPath();
    for(var j = 1; j < w; ++j){
        var x1 = client_to_x(j-1);
        var x2 = client_to_x(j);
        var y1 = 0.0;
        var y2 = 0.0;
        if(x1 > spline_xs[0] &&