ZedGraph绘制折线图的时候，Y轴的刻度大小及步长如何定义

private void Form4_Load(object sender, EventArgs e)        {            CreateChart(zedGraphControl1);        }public void CreateChart(ZedGraphControl zgc)        {            GraphPane myPane = zgc.GraphPane;            // Set the titles and axis labels            myPane.Title.Text = "生产线产量分析图";            //myPane.XAxis.Title.Text = "时间段";            //myPane.YAxis.Title.Text = "Pressure, Psia";            myPane.XAxis.Title.IsVisible = false;            myPane.YAxis.Title.IsVisible = false;            myPane.XAxis.MajorGrid.IsVisible = true;  //珊格子            myPane.YAxis.MajorGrid.IsVisible = true;            string[] labels = { "7~8点", "8~9点", "9~10点", "10~11点", "11~12点", "12~13点", "13~14点","14~15点" ,"15~16点","16~17点","17~18点"};            double[] y = { 2000, 1000, 5000, 2500, 3500, 7500,4000,5200};            double[] x = { 4000, 3000, 2500, 3500, 1500, 5500, 2000};            // Hide the legend            myPane.Legend.IsVisible = true;            // Add a curve            LineItem curve = myPane.AddCurve("总产量", null,y, Color.Red, SymbolType.Diamond);            curve.Line.Width = 2.0F;            curve.Line.IsAntiAlias = true;            curve.Symbol.Fill = new Fill(Color.White);            curve.Symbol.Size = 7;            LineItem curve1 = myPane.AddCurve("C线产量", null, x, Color.Blue, SymbolType.Circle);            curve1.Line.Width = 2.0F;            curve1.Line.IsAntiAlias = true;            curve1.Symbol.Fill = new Fill(Color.White);            curve1.Symbol.Size = 7;            // Fill the axis background with a gradient            myPane.Chart.Fill = new Fill(Color.White, Color.FromArgb(255, Color.ForestGreen), 45.0F);            // Offset Y space between point and label            // NOTE:  This offset is in Y scale units, so it depends on your actual data            const double offset = 1.0;            // Loop to add text labels to the points            for (int i = 0; i < y.Length; i++)            {                // Get the pointpair                PointPair pt = curve.Points[i];                // Create a text label from the Y data value                TextObj text = new TextObj(pt.Y.ToString("f2"), pt.X, pt.Y + offset,                    CoordType.AxisXYScale, AlignH.Left, AlignV.Center);                text.ZOrder = ZOrder.A_InFront;                // Hide the border and the fill                text.FontSpec.Border.IsVisible = false;                text.FontSpec.Fill.IsVisible = false;                //text.FontSpec.Fill = new Fill( Color.FromArgb( 100, Color.White ) );                // Rotate the text to 90 degrees                text.FontSpec.Angle = 50;  //字体倾斜度                myPane.GraphObjList.Add(text);            }            for (int i = 0; i < x.Length; i++)            {                // Get the pointpair                PointPair pt = curve1.Points[i];                // Create a text label from the Y data value                TextObj text = new TextObj(pt.Y.ToString("f2"), pt.X, pt.Y + offset,                    CoordType.AxisXYScale, AlignH.Left, AlignV.Center);                text.ZOrder = ZOrder.A_InFront;                // Hide the border and the fill                text.FontSpec.Border.IsVisible = false;                text.FontSpec.Fill.IsVisible = false;                //text.FontSpec.Fill = new Fill( Color.FromArgb( 100, Color.White ) );                // Rotate the text to 90 degrees                text.FontSpec.Angle = 50;  //数值字体倾斜度                myPane.GraphObjList.Add(text);            }            // Leave some extra space on top for the labels to fit within the chart rect            //myPane.YAxis.Scale.MaxGrace = 0.2;                        myPane.XAxis.Type = AxisType.Text;            myPane.XAxis.Scale.TextLabels = labels;            myPane.XAxis.Scale.FontSpec.Size = 8; //x线字体            myPane.XAxis.Scale.FontSpec.Angle = 60;//x线字体倾斜度            // Calculate the Axis Scale Ranges            zgc.AxisChange();        }