r - How to add custom labels from a dataset on top of bars using ggplot/geom_bar in R?

Question

I have the attached datasets and use this R code to plot the data:

plotData <- read.csv("plotdata.csv")
ix <- 1:nrow(plotData)
long <- melt(transform(plotData, id = ix), id = "id") # add id col; melt to long form
ggp2 <- ggplot(long, aes(id, value, fill = variable))+geom_bar(stat = "identity", position = "dodge")+
    scale_x_continuous(breaks = ix) +
    labs(y='Throughput (Mbps)',x='Nodes') +
    scale_fill_discrete(name="Legend",
                        labels=c("Inside Firewall (Dest)",
                                 "Inside Firewall (Source)",
                                 "Outside Firewall (Dest)",
                                 "Outside Firewall (Source)")) +
    theme(legend.position="right") +  # The position of the legend
    theme(legend.title = element_text(colour="blue", size=14, face="bold")) + # Title appearance
    theme(legend.text = element_text(colour="blue", size = 12, face = "bold")) # Label appearance
plot(ggp2)

The resulting plot is attached as well.

Now I need to add numbers from different datasets on top of each bar. For example:

1. on top of "Inside Firewall (Dest)" should be the numbers from sampleNumIFdest.csv
2. on top of "Inside Firewall (Source)" should be the numbers from sampleNumIFsource.csv
3. on top of "Outside Firewall (Dest)" should be the numbers from sampleNumOFdest.csv
4. on top of "Outside Firewall (Source)" should be the numbers from sampleNumOFsource.csv

I have tried to use geom_text() but I do not know how to read the numbers from the different datasets. Please note, that the datasets have different number of rows (which causes additional problems for me). Any suggestion is highly appreciated.

The attached files are here.

Sorry, I had to zip all my files as I am not allowed to add more then 2 URLs in my post.

Answer 1

我认为最好的解决方案是将所有数据集合并为一个：

# loading the different datasets
plotData <- read.csv("plotData.csv")
IFdest <- read.table("sampleNumIFdest.csv", sep="\t", header=TRUE, strip.white=TRUE)
IFsource <- read.table("sampleNumIFsource.csv", sep="\t", header=TRUE, strip.white=TRUE)
OFdest <- read.table("sampleNumOFdest.csv", sep="\t", header=TRUE, strip.white=TRUE)
OFsource <- read.table("sampleNumOFsource.csv", sep="\t", header=TRUE, strip.white=TRUE)

# add an id
ix <- 1:nrow(plotData)
plotData$id <- 1:nrow(plotData)
plotData <- plotData[,c(5,1,2,3,4)]

# combine the different dataframe
plotData$IFdest <- c(IFdest$Freq, NA)
plotData$IFsource <- c(IFsource$Freq, NA, NA)
plotData$OFdest <- OFdest$Freq
plotData$OFsource <- c(OFsource$Freq, NA, NA)

# reshape the dataframe
long <- cbind(
  melt(plotData, id = c("id"), measure = c(2:5),
       variable = "type", value.name = "value"),
  melt(plotData, id = c("id"), measure = c(6:9),
       variable = "name", value.name = "numbers")
)
long <- long[,-c(4,5)] # this removes two unneceassary columns

完成后，您可以使用geom_text在条形顶部绘制数字：

# create your plot
ggplot(long, aes(x = id, y = value, fill = type)) +
  geom_bar(stat = "identity", position = "dodge") +
  geom_text(aes(label = numbers), vjust=-1, position = position_dodge(0.9), size = 3) +
  scale_x_continuous(breaks = ix) +
  labs(x = "Nodes", y = "Throughput (Mbps)") +
  scale_fill_discrete(name="Legend",
                      labels=c("Inside Firewall (Dest)",
                               "Inside Firewall (Source)",
                               "Outside Firewall (Dest)",
                               "Outside Firewall (Source)")) +
  theme_bw() +
  theme(legend.position="right") +
  theme(legend.title = element_text(colour="blue", size=14, face="bold")) + 
  theme(legend.text = element_text(colour="blue", size=12, face="bold"))

结果：

如您所见，文本标签有时会重叠。你可以通过减小文本的大小来改变它，但是你会冒标签变得难以阅读的风险。因此，您可能会考虑通过在绘图代码中添加facet_grid(type ~ .)（或）来使用构面：facet_wrap(~ type)

ggplot(long, aes(x = id, y = value, fill = type)) +
  geom_bar(stat = "identity", position = "dodge") +
  geom_text(aes(label = numbers), vjust=-0.5, position = position_dodge(0.9), size = 3) +
  scale_x_continuous("Nodes", breaks = ix) +
  scale_y_continuous("Throughput (Mbps)", limits = c(0,1000)) +
  scale_fill_discrete(name="Legend",
                      labels=c("Inside Firewall (Dest)",
                               "Inside Firewall (Source)",
                               "Outside Firewall (Dest)",
                               "Outside Firewall (Source)")) +
  theme_bw() +
  theme(legend.position="right") +
  theme(legend.title = element_text(colour="blue", size=14, face="bold")) + 
  theme(legend.text = element_text(colour="blue", size=12, face="bold")) +
  facet_grid(type ~ .)

结果如下图：