在图表上绘制多条线：geom_path：每组仅包含一个观测值。您是否需要调整小组审美？

Question

我试图在图表上绘制多条线，我的代码如下所示：

ggplot(Data_UK_onTrea, aes(x = years, y = value )) +
  geom_line(aes(color = region, linetype = sex))

我的数据显示如下：

structure(list(years = structure(c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 
8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 
3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 
8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 
3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 
8L, 9L, 10L, 1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L), .Label = c("2009", 
"2010", "2011", "2012", "2013", "2014", "2015", "2016", "2017", 
"2018"), class = "factor"), region = structure(c(1L, 1L, 1L, 
1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 
4L, 4L, 4L, 4L, 4L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 
2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 4L), .Label = c("England", 
"Wales", "Northern Ireland", "Scotland"), class = "factor"), 
    sex = c("Male", "Male", "Male", "Male", "Male", "Male", "Male", 
    "Male", "Male", "Male", "Male", "Male", "Male", "Male", "Male", 
    "Male", "Male", "Male", "Male", "Male", "Male", "Male", "Male", 
    "Male", "Male", "Male", "Male", "Male", "Male", "Male", "Male", 
    "Male", "Male", "Male", "Male", "Male", "Male", "Male", "Male", 
    "Male", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female", "Female", 
    "Female", "Female", "Female", "Female", "Female"), value = c(39611, 
    42188, 44874, 47665, 50100, 53018, 56121, 58005, 59600, 60168, 
    884, 996, 1114, 1158, 1256, 1411, 1480, 1548, 1625, 1695, 
    322, 366, 444, 511, 592, 633, 734, 787, 861, 894, 2149, 2314, 
    2538, 2665, 2914, 2962, 3100, 3162, 3385, 3494, 20868, 21999, 
    23102, 23995, 24542, 25686, 26289, 26773, 27376, 27662, 320, 
    340, 384, 400, 426, 453, 463, 481, 491, 509, 126, 135, 138, 
    160, 179, 181, 211, 221, 224, 236, 961, 1031, 1109, 1124, 
    1157, 1160, 1195, 1206, 1284, 1304)), class = "data.frame", row.names = c(NA, 
-80L))

但是当我运行代码时，图表上没有线：

enter image description here

我将不胜感激。

Answer 1

最简单的解决方案是将years从一个因子更改为一个数字变量

Data_UK_onTrea$years <- as.numeric(as.character(Data_UK_onTrea$years))

ggplot(Data_UK_onTrea, aes(x = years, y = value )) +
  geom_line(aes(color = region, linetype = sex))

line graph

Answer 2

“年”列是一个因素：

> str(Data_UK_onTrea)
'data.frame':   80 obs. of  4 variables:
 $ years : Factor w/ 10 levels "2009","2010",..: 1 2 3 4 5 6 7 8 9 10 ...
 $ region: Factor w/ 4 levels "England","Wales",..: 1 1 1 1 1 1 1 1 1 1 ...
 $ sex   : chr  "Male" "Male" "Male" "Male" ...
 $ value : num  39611 42188 44874 47665 50100 ...

现在将年份转换为数字：

Data_UK_onTrea$years = as.numeric(as.character(Data_UK_onTrea$years)) 

ggplot(Data_UK_onTrea, aes(x = years, y = value )) +
  geom_line(aes(color = region, linetype = sex))

我不确定您如何得出一个因子，但是您在执行read.table时可以指定stringsAsFactors = F，也可以执行上述str（）来检查变量。