Question

我尝试获取Y轴显示的值，但似乎无法解决问题，这是我的代码以及除数据外的绘图结果：

library(ggplot2)

traffic.data <- structure(list(years = 2008:2017, units = structure(c(1L, 2L, 4L, 5L, 3L, 6L, 7L, 8L, 9L, 10L), .Label = c("12,866,461", "13,350,011", "15,106,666", "15,361,841", "15,669,918", "16,498,204", "17,296,885", "17,611,762", "18,239,288", "20,359,883"), class = "factor")), .Names = c("years", "units"), class = "data.frame", row.names = c(NA, -10L))

traffic.data
       years     units
#  1   2008 12,866,461
#  2   2009 13,350,011
#  3   2010 15,361,841
#  4   2011 15,669,918
#  5   2012 15,106,666
#  6   2013 16,498,204
#  7   2014 17,296,885
#  8   2015 17,611,762
#  9   2016 18,239,288
# 10  2017  20,359,883

ggplot(traffic.data, aes(x = years, y = as.numeric(units))) + 
   geom_point() +
   geom_line() +
   scale_x_continuous(breaks = seq(2008, 2017, 1)) + 
   scale_y_continuous(breaks = seq(10000000,30000000,1)) +
   labs(x = "years", y = "total traffic of passengers", 
        title = "evolution of traffic during the past 10 years")

运行此代码时，我得到以下折线图，缺少Y轴的值：

Answer 1

问题1：

scale_y_continuous(breaks = seq(10000000,30000000,1))

因此，您正尝试从1千万增加到30百万。

问题2：

  +   labs(x = "years", y = "total traffic of passengers", 
    +        title = "evolution of traffic during the past 10 years")

在这一行中，您不需要第二个+，这会引起问题。

此数据对我来说很好

dt<-data.frame(years=c(2008:2018),
               units=sample(c(15000000:20000000),11,replace = T))
dt

和此代码：

       ggplot(dt, aes(x=years, y=units))+
   geom_point(data=NULL)+
   geom_line(data=NULL) + 
   scale_y_continuous(breaks = seq(10000000,30000000,1000000)) + 
   labs(x = "years", y = "total traffic of passengers",
        title = "evolution of traffic during the past 10 years")

这是结果：

Answer 2

数据集

# example dataset
df = structure(list(years = 2008:2017, 
                    units = structure(c(1L, 2L, 4L, 5L, 3L, 6L, 7L, 8L, 9L, 10L), .Label = c("12,866,461", "13,350,011", "15,106,666", "15,361,841", "15,669,918", "16,498,204", "17,296,885", "17,611,762", "18,239,288", "20,359,883"), class = "factor")), 
              .Names = c("years", "units"), class = "data.frame", row.names = c(NA, -10L))

问题

您的units列为factor，将其更新为数字非常棘手。检查一下：

as.numeric(df$units)
# [1]  1  2  4  5  3  6  7  8  9 10

这些是您在y轴上绘制的值。这就是为什么无论实际数字是多少，点之间的距离似乎都相同的原因，这就是为什么这些值也没有显示在y轴上的原因，因为您指定了scale_y_continuous(breaks = seq(10000000,30000000,1))（即从3mil开始）。

解决方案

# update column
df$units = as.numeric(gsub(",", "", as.character(df$units), fixed = TRUE))

library(ggplot2)

ggplot(df, aes(x=years, y=units)) +
  geom_point() +
  geom_line() + 
  scale_x_continuous(breaks = seq(2008,2017,1))+ 
  scale_y_continuous(breaks = seq(10000000,30000000,1000000)) +
  labs(x = "years", y = "total traffic of passengers", title = "evolution of traffic during the past 10 years")

请注意，我已将您的y轴值之间的步长/距离更改为1mil。步长= 1将使处理过程变慢，并且绘图不可读。

在绘制之前，您可以使用options(scipen = 999)，以避免用科学的数字表示法。

ggplot2不显示Y轴的值

2 个答案: