R 如何使用ggplot2打印有效行数

使用数据帧作为

df <- data.frame(name = c("a", "b", "c", "d", "e"),
             class = c("a1", "a1", "a1", "b1", "b1"),
             var1 = c("S", "S", "R", "S", "S"),
             var2 = c("S", "R", NA, NA, "R"),
             var3 = c(NA, "R", "R", "S", "S"))

df_count <- matrix(nrow=3, ncol=2)
df_count <- as.data.frame(df_count)
names(df_count) <- c("var_num", "count")
df_count$var_num <- as.factor(names(df)[3:5])
for (i in 1:3) {
    df_count[i,2] <- sum(!is.na(df[,i+2]))
}

有没有一种更简单的方法可以选择var1到var3，并在不生成新数据帧的情况下计算有效行数？

library（'ggplot2'））
library('ggplot2')
library('reshape2')

df <- melt(df, id.vars = c('name', 'class'))  # melt data
df <- df[!is.na(df$value), ]                  # remove NA
df <- with(df, aggregate(df, by = list(variable), FUN = length )) # compute length by grouping variable

ggplot(df, aes( x = Group.1, y = value, fill = Group.1 )) + 
   geom_bar(stat="identity")

库（'reformae2'）
df不管怎样，您都需要将形状改为长形，但是
geom_bar
的
stat_count
可以为您聚合，例如
库（tidyverse）；df%%>%聚集（var，val，以（'var'）开始）%%>%drop\u na（val）%%>%ggplot（aes（var，fill=val））+geom\u bar（）
library('ggplot2')
library('reshape2')

df <- melt(df, id.vars = c('name', 'class'))  # melt data
df <- df[!is.na(df$value), ]                  # remove NA
df <- with(df, aggregate(df, by = list(variable), FUN = length )) # compute length by grouping variable

ggplot(df, aes( x = Group.1, y = value, fill = Group.1 )) + 
   geom_bar(stat="identity")

df <- melt(df, id.vars = c('name', 'class'))  # melt data
df <- df[!is.na(df$value), ]                  # remove NA
df <- with(df, aggregate(df, by = list(variable, value), FUN = length )) # compute length by grouping variable and value

ggplot(df, aes( x = Group.1, y = value, fill = Group.2 )) + 
  geom_bar(stat="identity")

df <- data.frame(name = c("a", "b", "c", "d", "e"),
                 class = c("a1", "a1", "a1", "b1", "b1"),
                 var1 = c("S", "S", "R", "S", "S"),
                 var2 = c("S", "R", NA, NA, "R"),
                 var3 = c(NA, "R", "R", "S", "S"))