public class GraphDrawer
        {
            private Graphics mGraphics;
            private PictureBox mPictureBox;

            public GraphDrawer (PictureBox pb)
            {
                mPictureBox = pb;
                mGraphics = pb.CreateGraphics();
                clear();
            }

            public void draw (double[] ys, bool clear)
            {
                double h = Convert.ToDouble(mPictureBox.Width) / (ys.Length - 1);
                if (clear)
                    mGraphics.Clear(Color.White);

                double min = getMinFromArray(ys), max = getMaxFromArray(ys);

                double yAxisZero = max;
                for (int i = 0; i < ys.Length; ++i)
                {

                    ys[i] = max - ys[i];
                }
                min = getMinFromArray(ys); max = getMaxFromArray(ys);

                double dHeight = mPictureBox.Height / (max - min) - 0.1;
                //double dHeight = (max - min) / mPictureBox.Height;\
                yAxisZero -= min;
                yAxisZero *= dHeight;
                for (int i = 0; i < ys.Length; ++i)
                {
                    ys[i] -= min;
                    ys[i] *= dHeight;
                }

                for (int i = 0; i < ys.Length - 1; ++i)
                {
                    mGraphics.DrawLine(Pens.Black,
                        (float) h * i,
                        (float) (ys[i]),
                        (float) h * (i + 1),
                        (float) (ys[i + 1])
                        );
                }
                Pen axisPen = new Pen(Color.Red);
                //axisPen.EndCap = System.Drawing.Drawing2D.LineCap.ArrowAnchor;
                mGraphics.DrawLine(axisPen, 0, (float) (yAxisZero), mPictureBox.Width /*- 5*/, (float) (yAxisZero));
            }

            private double getMinFromArray(double[] arr)
            {
                double min = Double.MaxValue;
                for (int i = 0; i < arr.Length; ++i)
                {
                    if (min > arr[i])
                        min = arr[i];
                }
                return min;
            }

            private double getMaxFromArray(double[] arr)
            {
                double max = Double.MinValue;
                for (int i = 0; i < arr.Length; ++i)
                {
                    if (max < arr[i])
                        max = arr[i];
                }
                return max;
            }

            internal void clear()
            {
                mGraphics.Clear(Color.White);
            }
        }