桑基图（Sankey diagram），即桑基能量分流图，也叫桑基能量平衡图。它是一种特定类型的流程图，图中延伸的分支的宽度对应数据流量的大小，通常应用于能源、材料成分、金融等数据的可视化分析。

第一列为上游，第二列为下游，第三列为联通值，值越大线越粗。如果您自己有数据，只需要替换输入部分，后面数据格式转换代码是通用的。

例1：

library(networkD3)
network <- 
    "Src;Target;Value
    Bioinfo;Biology;20
    Bioinfo;Math;20
    Bioinfo;Program;20
    Bioinfo;NGS;20
    Program;Linux;8
    Program;Python;8
    Program;R;6
    NGS;RNAseq;1
    NGS;ChIPseq;1
    NGS;m16Sseq;1
    NGS;Metagenome;1
    NGS;SingeCellSeq;1
    NGS;DNAmethylseq;1
    NGS;lncRNA;1
    NGS;Exomeseq;1
    NGS;TCGA;1
    "

network <- read.table(text=network, sep=";", 
                      header=T, row.names=NULL, quote="", comment="")

network <- network[,1:3]
colnames(network) <- c("Src", "Target", "Value")

factor_list <- sort(unique(c(levels(network$Src), levels(network$Target))))
num_list <- 0:(length(factor_list)-1)
levels(network$Src) <- num_list[factor_list %in% levels(network$Src)]
levels(network$Target) <- num_list[factor_list %in% levels(network$Target)]

network$Src <- as.numeric(as.character(network$Src))
network$Target <- as.numeric(as.character(network$Target))

attribute <- data.frame(name=c(factor_list))

sankeyNetwork(Links = network, Nodes = attribute,
              Source = "Src", Target = "Target",
              Value = "Value", NodeID = "name",
              fontSize= 12, nodeWidth = 30)

例2：

library(networkD3)
nodes = data.frame("name" = 
  c(
  "Node A", # Node 0
  "Node B", # Node 1
  "Node C", # Node 2
  "Node D"  # Node 3
  ))

links = as.data.frame(matrix(c(
  0, 1, 10, # Each row represents a link. The first number             node 0 和 1 之间的线粗为10
  0, 2, 20, # represents the node being conntected from. 
  1, 3, 30, # the second number represents the node connected to.      node 1 和 3之间的线粗为30
  2, 3, 40),# The third number is the value of the node
  byrow = TRUE, ncol = 3))

names(links) = c("source", "target", "value")

sankeyNetwork(Links = links, Nodes = nodes,
               Source = "source", Target = "target",
               Value = "value", NodeID = "name",
               fontSize= 12, nodeWidth = 30)