在graphviz中增加边缘的分离答案

【问题标题】：Increase separation of edges in graphviz在graphviz中增加边缘的分离
【发布时间】：2016-08-16 23:53:09
【问题描述】：

我正在使用 dot-graphviz 创建几个 UML 活动图，只要目标形状是窄矩形（H=0.5，W=0.05），边/箭头 (2+) 就会收敛在同一点。如果目标形状是正方形（H=0.5，W=0.5），则不会出现此问题。

这是一个减少点的例子：

digraph G {
graph [ ranksep = 0.5, rankdir = LR ]
A4 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rPreviewer", style = "rounded" ]
A5 [ shape = "rectangle", height = 0.5, width = 0.05, margin = "0,0", style = "filled", label = "" ]
A4 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
A6 [ shape = "diamond", height = 0.5, width = 0.5, margin = "0,0", label = "" ]
A6 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label = "[generate: false]" ]
A7 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rFile", style = "rounded" ]
A6 -> A7 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label = "[generate: true]" ]
A8 [ shape = "doublecircle", height = 0.3, width = 0.3, margin = "0,0", label = "" ]
A7 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
A5 -> A8 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
}

以上文字在http://webgraphviz.com中生成如下图

理想的输出如下

【问题讨论】：

你可以试试A6 -> A5:nw 和A7 -> A5:sw。不能准确地给您想要的输出，但至少可以分离边缘。
@vaettchen，这听起来不像是一个通用的解决方案，而且对于提供的示例来说非常具体。如果有 4 个边也没有用。
正确 - 我尝试了针对该特定问题的解决方案。也许您编辑您的帖子说您正在寻找更多边缘/箭头的通用解决方案。

标签： graphviz dot

【解决方案1】：

我发现了一个可以产生不错输出的调整，但需要大量的处理以及边缘计数和方向意识：

digraph G {
graph [ ranksep = 0.5, rankdir = LR ]
A4 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rPreviewer", style = "rounded" ]
A5 [ shape = "record", height = 0.5, width = 0.05, margin = "0,0", style = "filled", label = "<f0>|<f1>|<f2>", fillcolor="black" ]
A4 -> A5:f0:w [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
A6 [ shape = "diamond", height = 0.5, width = 0.5, margin = "0,0", label = "" ]
A6 -> A5:f1:w [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label = "[generate: false]" ]
A7 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rFile", style = "rounded" ]
A6 -> A7 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label = "[generate: true]" ]
A8 [ shape = "doublecircle", height = 0.3, width = 0.3, margin = "0,0", label = "" ]
A7 -> A5:f2:w [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
A5 -> A8 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
}

这是输出：

我仍然想知道是否有更简单的解决方案。

【讨论】：

我接受我自己的答案，因为它产生了最好的结果，并且可以扩展到任意数量的边缘。

【解决方案2】：

您可以将所有边的输出端口指定为east 并获得非常好的结果（至少在这种情况下）：

digraph G {
        graph [ ranksep = 0.5, rankdir = LR ]
        edge [tailport=e]                    # <----- added this line
        A4 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rPreviewer", style = "rounded" ]
        A5 [ shape = "rectangle", height = 0.5, width = 0.05, margin = "0,0", style = "filled", label = "" ]
        A4 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
        A6 [ shape = "diamond", height = 0.5, width = 0.5, margin = "0,0", label = "" ]
        A6 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label     = "[generate: false]" ]
        A7 [ shape = "record", height = 0.5, fontsize = 10, margin = "0.20,0.05", label = "Output\ to\rFile", style = "rounded" ]
        A6 -> A7 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10, label     = "[generate: true]" ]
        A8 [ shape = "doublecircle", height = 0.3, width = 0.3, margin = "0,0", label = "" ]
        A7 -> A5 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
        A5 -> A8 [ shape = "edge", dir = "both", style = "solid", arrowtail = "none", arrowhead = "vee", labeldistance = 1, fontsize = 10 ]
}

生产：

【讨论】：

您好 Ohad，乍一看，它看起来是一个不错的选择，但这只是所提供示例的巧合。尝试评论A7 -> A5这一行，原来的效果又出现了。
虽然这不是巧合，但你是对的，它并不是适用于所有情况的解决方案