Graphviz如何控制边缘

我对你的图表做了一些修改,以使你更接近。样条曲线的多段线,并更改了1和2节点的属性,使其更接近您的目标。显然并不完美,但希望能更好地提供帮助并提出其他方法,您可以在不进行重大重新设计的情况下进一步改进它。

digraph M
{
  style=filled;
  graph [splines = headport splines=polyline];

  START->1
  1->"Is COUNT\nan even\nnumber?"
  "Is COUNT\nan even\nnumber?"->"SUM = SUM +\nCOUNT" [label=TRUE]
  "SUM = SUM +\nCOUNT"->2
  "Is COUNT\nan even\nnumber?"->2 [label=FALSE]
  2->"COUNT = COUNT+1" 
  "COUNT = COUNT+1"->"IS COUNT >\n20"
  "IS COUNT >\n20"->1 [label=FALSE tailport=e]
  "IS COUNT >\n20"->STOP[label=TRUE ]


  "Is COUNT\nan even\nnumber?"[shape=diamond]
  "SUM = SUM +\nCOUNT"[shape=rectangle]
  "IS COUNT >\n20"[shape=diamond]
  "COUNT = COUNT+1"[shape=rectangle headport=n]
  1[shape=point size="0,0" label=""]
  2[shape=point size="0,0" label=""]
  START[shape=record, style="rounded"]
  STOP[shape=record, style="rounded"]
}