求助 画了个饼状图，但显示的比例有问题

Question

      public enum MapTypes
      {          饼状图,
          折线图,
          柱状图      }
      public int Xuan
      {
          get
          {
              return xuan;
          }
          set
          {
              xuan = value;
              Invalidate();
          }
      }
      public float Beiy
      {
          get
          {
              return beiy;
          }
          set
          {
              beiy = value;
              Invalidate();
          }
      }
      public float Beix
      {
          get
          {
              return beix;
          }
          set
          {
              beix = value;
              Invalidate();
          }
      }
      
      public string Biaoti
      {
          get
          {
              return biaoti;
          }
          set
          {
              biaoti = value;
              Invalidate();
          }
      }
     
      public int Biaotizihao
      {
          get
          {
              return biaotizihao;
          }
          set
          {
              biaotizihao = value;
              Invalidate();
          }
      }
      public int Biaotizigao
      {
          get
          {
              return biaotizigao;
          }
          set
          {
              biaotizigao = value;
              Invalidate();
          }
      }
   
      public int Gsx
      {
          get
          {
              return gsx;
          }
          set
          {
              gsx = value;
              Invalidate();
          }
      }
    
      public int Gsy
      {
          get
          {
              return gsy;
          }
          set
          {
              gsy = value;
              Invalidate();
          }
      }
      public Point Jiao
      {
          get
          {
              return jiao;
          }
          set
          {
              jiao = value;
              Invalidate();
          }
      }
      public int Zihao
      {
          get
          {
              return zihao;
          }
          set
          {
              zihao = value;
              Invalidate();
          }
      }
      //     [DefaultValue("要输入的标题")]
      public float[] Zhi
      {          get
          {
                            return zhi;
          }
          set
          {
              zhi = value;
              Invalidate();
          }
      }
      public string[] Zhimiaoshu
      {          get
          {
                           return zhimiaoshu;
          }
          set
          {
              zhimiaoshu = value;
              Invalidate();
          }
      }
      //*/
      //  [DefaultValue("要输入的标题")]
      public string Dany
      {
          get
          {
              return dany;
          }
          set
          {
              dany = value;
              Invalidate();
          }
      }
      public string Danx
      {
          get
          {
              return danx;
          }
          set
          {
              danx = value;
              Invalidate();
          }
      }
      public MapTypes MapType
      {          get
          {
              return mapType;
          }
          set
          {
              mapType = value;
          }
      }      public tjzhu()
      {
          InitializeComponent();
          // this.shezhi();      }     
      private Color GetColor(int ValueIndex)
      {
          Color ColorTemp;
          switch (ValueIndex)
          {
              case 0: //红色 
                  ColorTemp = Color.FromArgb(235, 0, 0);
                  break;
              case 1:
                  ColorTemp = Color.FromArgb(142, 235, 235);
                  break;
              case 2:
                  ColorTemp = Color.FromArgb(0, 192, 192);
                  break;
              case 3:
                  ColorTemp = Color.FromArgb(235, 216, 177);
                  break;
              case 4:
                  ColorTemp = Color.FromArgb(189, 167, 225);
                  break;
              case 5:
                  ColorTemp = Color.FromArgb(0xff, 0xe4, 0xe1);
                  break;
              case 6:
                  ColorTemp = Color.FromArgb(0x00, 0x00, 0xff);
                  break;
              case 7:
                  ColorTemp = Color.FromArgb(0x80, 0x80, 0x00);
                  break;
              case 8:
                  ColorTemp = Color.FromArgb(0x48, 0xd1, 0xcc);
                  break;
              case 9:
                  ColorTemp = Color.FromArgb(0xbc, 0x8f, 0x8f);
                  break;
              case 10:
                  ColorTemp = Color.FromArgb(0xad, 0xd8, 0xe6);
                  break;
              case 11:
                  ColorTemp = Color.FromArgb(0x94, 0x00, 0xd3);
                  break;
              case 12:
                  ColorTemp = Color.FromArgb(0x00, 0x8b, 0x8b);
                  break;
              case 13:
                  ColorTemp = Color.FromArgb(0xaf, 0xee, 0xee);
                  break;
              case 14:
                  ColorTemp = Color.FromArgb(0x7b, 0x68, 0xee);
                  break;
              case 15:
                  ColorTemp = Color.FromArgb(0xf0, 0xf8, 0xff);
                  break;
              case 16:
                  ColorTemp = Color.FromArgb(0xb8, 0x86, 0x0b);
                  break;
              case 17:
                  ColorTemp = Color.FromArgb(0xff, 0xd7, 0x00);
                  break;
              case 18:
                  ColorTemp = Color.FromArgb(0x32, 0xcd, 0x32);
                  break;
              case 19:
                  ColorTemp = Color.FromArgb(0x00, 0xfa, 0x9a);
                  break;
              default:
                  ColorTemp = Color.Black;
                  break;
          }
          return ColorTemp;
      } 
       
       
    }
}
我还用30，60等角度试过，比例都不准，不知道为什么，希望高手帮下，谢谢

Answer 1

大部分情况下是由于小数点引起的误差造成的.尝试修改一下计算公式里的函数

Answer 2

同样的数据相差接近1倍，不是小数的问题

Answer 3

有做了个实验，图越接近圆形比例就越准，越扁就越失真，有什么方法可以矫正吗？希望高手指点下，本人新手，万分感谢！！！！！！！！！

Answer 4

画的时候按正圆画,然后再建一个宽度相同但高度只有一半差不多的图,把结果图画上去,就变形了.但还是那句话:小数点影响比例,长期以来我也是对此比较头痛的.以下是我以前做的,两张图中都有明显的因小数点引起的偏差扩大.

Answer 5

相同的数据，差的太多了

Answer 6

百分比是一样的，中间的两个也太小了
看了你编的图片，我都自卑了，打击我信心啊！

Answer 7

呵,有什么打击不打击的.我偏向于喜欢去创作人机界面,不擅长做数据.相信自己,我期待你成功.