如何在Gnuplot中绘制具有加权边的树/图/网页？ [英] How to plot a tree/graph/web with weighted edges in Gnuplot?

问题描述

我正在这里讨论如何绘制一个gnuplot树（

解决方案

我会针对您在问题中提到的答案提出一些细微的变化。假设顶点的坐标存储在文件 pnts.dat 中，如下所示：

  0 5 10 
 1 20 20 
 2 15 15 
 3 30 30 
 4 40 10 
  

这里，第一列记录相应的标签，第二列和第三列分别包含x和y坐标。

边缘可以在单独的文件 edges.dat 中定义为：

  0 1 30 0 1 
 1 2 40 0 -2 
 1 4 20 0 1 
 1 3 10 0 1 
  

这里，前两列包含点索引（它们指的是 pnts.dat ）。第三列记录特定边的权重。最后，最后两列包含生成的相关标签的x，y位移。

这样，Gnuplot脚本可能如下所示：

 设置xr [0:50] 
设置年[0:50] 
 
设置尺寸平方
 
 flePnts ='pnts.dat'
 fleEdges ='edges.dat'
 
 loadEdges = sprintf（'< gawk''\ 
 FNR == NR {x [$ 1] = $ 2; y [$ 1] = $ 3; next;} \ 
 {printf%% f\t %% f\\\
 %% f\t %% f\ n \ n，x [$ 1]，y [$ 1]，x [$ 2]，y [$ 2];} \ 
''％s％s'，flePnts，fleEdges）; 
 
 loadWeights = sprintf（'< gawk''\ 
 FNR == NR {x [$ 1] = $ 2; y [$ 1] = $ 3; next;} \ 
 {printf%% f\t %% f\t %% s\\\
，（x [$ 1] + x [$ 2]）/ 2 + $ 4，（y [$ 1] + y [$ 2 ]）/ 2 + $ 5，$ 3} \ 
''％s％s'，flePnts，fleEdges）; 
 
 plot \ 
使用1：2加载行的加载边线lc rgbblacklw 2 notitle，\ 
 flePnts使用2：3：（0.6） lc rgbblacknotitle，\ 
 flePnts使用带标签的2：3：1 tc rgbwhite字体Arial Boldnotitle，\ 
 loadWeights使用带标签的1：2：3 tc rgbredcenter字体Arial Boldnotitle 
  

1. loadEdges 命令调用 gawk ，以便为所有边缘生成相应的x / y坐标对（用空行分隔）


2. loadWeights 为每条边计算中间点并在这些坐标处放置一个标签（考虑到所需的偏移量）

最后，获得：

i am plotting a tree in gnuplot as discussed here (How to plot tree/graph/web data on gnuplot?). However, i would like to include the edges weight of the tree, i.e. for each edge i have a number (e.g. 10, 20, 30, 40) that represents the edge weight. The figure below shows in red the edges weight that i want to plot in gnuplot (i added this using power point).

Can anyone tell me how to plot edges with weight in gnuplot?

解决方案

I would propose a slight variation on the answer which you mention in your question. Let's assume that the coordinates of the vertices are stored in a file pnts.dat as follows:

0   5   10
1   20  20
2   15  15
3   30  30
4   40  10

Here, the first column records the corresponding label, while second and third columns contain the x- and y-coordinate, respectively.

The edges could be defined in a separate file edges.dat as:

0   1   30  0   1
1   2   40  0   -2
1   4   20  0   1
1   3   10  0   1

Here, the first two column contain the point indices (they refer to the first column of pnts.dat). The third column records the weight of a particular edge. Finally, the last two columns contain the x,y displacement of the generated associated label.

With this, the Gnuplot script could look like:

set xr [0:50]   
set yr [0:50]

set size square   

flePnts = 'pnts.dat'
fleEdges = 'edges.dat'

loadEdges = sprintf('< gawk '' \
    FNR==NR{x[$1]=$2;y[$1]=$3;next;} \
    {printf "%%f\t%%f\n%%f\t%%f\n\n", x[$1], y[$1], x[$2], y[$2];} \
'' %s %s', flePnts, fleEdges); 

loadWeights = sprintf('< gawk '' \
    FNR==NR{x[$1]=$2;y[$1]=$3;next;} \
    {printf "%%f\t%%f\t%%s\n", (x[$1]+x[$2])/2 + $4, (y[$1]+y[$2])/2 + $5, $3} \
'' %s %s', flePnts, fleEdges);

plot \
    loadEdges using 1:2 with lines lc rgb "black" lw 2 notitle, \
    flePnts using 2:3:(0.6) with circles fill solid lc rgb "black" notitle, \
    flePnts using 2:3:1 with labels tc rgb "white" font "Arial Bold" notitle, \
    loadWeights using 1:2:3 with labels tc rgb "red" center font "Arial Bold" notitle

1. the loadEdges command invokes gawk in order to generate for all edges the corresponding pairs of x/y coordinates (delimited by a blank line)
2. loadWeights calculates for each edge the middle point and places a label at these coordinates (taking into account the required offset)

Finally, one obtains:

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