请问一个绘制多图zedGraph的有关问题

请教一个绘制多图zedGraph的问题
我在绘制一个多图的zedGraph的时候 无法控制其中的的 GraphPane的高度和宽度，老是会出现 图的纵坐标显示不全，各个图的大小不好控制的情况。
我现在想显示3个曲线图在一个控件上。前两个图的大小太大，最后一个图的大小又太小，求教各位啦。

C# code

private void Form1_Load(object sender, EventArgs e)        {            MasterPane master = zedGraphControl1.MasterPane;            master.Fill = new Fill(Color.White, Color.FromArgb(220, 220, 255), 45.0f);            master.PaneList.Clear();            master.Title.IsVisible = true;            master.Title.Text = "感光电压曲线图";            master.Margin.All = 10;            master.InnerPaneGap = 0;            ColorSymbolRotator rotator = new ColorSymbolRotator();            for (int j = 0; j < 3; j++)            {                GraphPane myPaneT = new GraphPane(new Rectangle(40, 40, 500, 250),                    "Case #" + (j+1).ToString(),                    "时间",                    "电压");                myPaneT.Fill.IsVisible = false;                myPaneT.Chart.Fill = new Fill(Color.White, Color.LightYellow, 45.0F);                myPaneT.BaseDimension = 2.0F;                myPaneT.XAxis.Title.IsVisible = false;                myPaneT.XAxis.Scale.IsVisible = false;                myPaneT.Legend.IsVisible = false;                myPaneT.Border.IsVisible = false;                myPaneT.Title.IsVisible = false;                myPaneT.XAxis.MajorTic.IsOutside = false;                myPaneT.XAxis.MinorTic.IsOutside = false;                myPaneT.XAxis.MajorGrid.IsVisible = true;                myPaneT.XAxis.MinorGrid.IsVisible = true;                myPaneT.XAxis.Scale.Max = 50;                myPaneT.XAxis.Scale.Min = 0;                myPaneT.Margin.All = 0;                LineItem myCurve = null;                if (j == 0)                 {                    myPaneT.YAxis.Scale.MinorStep = 0.1;                    myPaneT.YAxis.Scale.MajorStep = 1;                    myPaneT.YAxis.Scale.Max = 5;                    myPaneT.YAxis.Scale.Min = 0;                    myPaneT.Margin.Top =0;                    myPaneT.YAxis.Title.Text = "I1";                    myCurve = myPaneT.AddCurve("Step " + j.ToString(), listI1, rotator.NextColor, SymbolType.None);                    myCurve.Line.StepType = StepType.ForwardStep;                    myCurve.Symbol.Fill = new Fill(Color.Red);                    master.Add(myPaneT);                    this.zedGraphControl1.AxisChange();                }                if(j==1)                {                    myPaneT.YAxis.Scale.MinorStep = 0.1;                    myPaneT.YAxis.Scale.MajorStep = 1;                    myPaneT.YAxis.Scale.Max = 5;                    myPaneT.YAxis.Scale.Min = 0;                    myPaneT.XAxis.Scale.MinorStep = 1;                    myPaneT.Margin.Top = 0;                    myPaneT.YAxis.Title.Text = "I2";                    myCurve = myPaneT.AddCurve("Step " + j.ToString(), listI2, rotator.NextColor, SymbolType.None);                    myCurve.Symbol.Fill = new Fill(Color.Red);                    master.Add(myPaneT);                    this.zedGraphControl1.AxisChange();                }                if (j == 2)                {                    //myPaneT.YAxis.Scale.Max = files.ReadInteger("SYSTEM", "DISPLAY_VOLTAGE2", 5);                    //myPaneT.YAxis.Scale.Min = files.ReadInteger("SYSTEM", "DISPLAY_VOLTAGE1", -5);                     myPaneT.XAxis.Title.IsVisible = true;                    myPaneT.XAxis.Scale.IsVisible = true;                    myPaneT.XAxis.Scale.MinorStep = 1;                    myPaneT.Margin.Top =0;                    myPaneT.YAxis.Title.Text = "I3";                    myCurve = myPaneT.AddCurve("Step " + j.ToString(), list, rotator.NextColor, SymbolType.None);                    myCurve.Symbol.Fill = new Fill(Color.Red);                    myPaneT.YAxis.Scale.Max=10;                    myPaneT.YAxis.Scale.Min= -10;                    master.Add(myPaneT);                    this.zedGraphControl1.AxisChange();                }                if (j > 0)                myPaneT.YAxis.Scale.IsSkipLastLabel = true;                myPaneT.YAxis.MinSpace =10;                myPaneT.Y2Axis.MinSpace =10;                //this.zedGraphControl1.AxisChange();                printMessage("窗体加载完成");            }            using (Graphics g = zedGraphControl1.CreateGraphics())            {                ZedGraphControl z1 = zedGraphControl1;                master.SetLayout(g, PaneLayout.SingleColumn);                z1.AxisChange();                z1.IsAutoScrollRange = true;                z1.IsShowHScrollBar = true;                z1.IsShowVScrollBar = true;                z1.IsSynchronizeXAxes = true;            }        }