我有data.table格式的数据，如下所示：
library(data.table)
dt
interval location type y_axis
01 40 "X" 20
01 136 "Y" 40
01 2803 "Z" 21
01 8973 "X" 32
.... ....
02 3219 "Z" 32
02 4074 "Z" 93
02 8015 "Z" 15
....
有几个间隔，例如01，02等。在每个时间间隔内，数据点位于1到10,000的范围内。在dt中，第一个数据点为40，下一个数据点为136，等等。
间隔02的范围也介于1到10,000之间。
我想创建一个散点图，使得每个间隔按比例绘制1到10000的范围。然后第一个点将绘制在40，下一个绘制在136，等等。我还想要一条垂直线，显示间隔的位置。
如果只有一个间隔，qplot
plotted = qplot(x=location, y= y_axis, colour = type, data=dt)
+ geom_vline(xintercept = c(unique(dt$interval)), linetype="dashed", color = "darkgray", size=1) # taking the first unique 'interval' value to be the boundary line
虽然多个时间间隔不起作用。 x=location将所有location个数据点排序在一起。
怎么会这样做？
编辑：这是dput(head(dt, 50))
interval = c("01",
"01", "01", "01", "01", "01", "01", "01", "01", "01", "01", "01",
"01", "01", "01", "01", "01", "01", "01", "01", "01", "01", "01",
"01", "01", "01", "01", "01", "01", "01", "01", "01", "01", "01",
"01", "01", "01", "01", "01", "01", "01", "01", "01", "01", "01",
"01", "01", "01", "01", "01"), location = c(1230, 1609,
1903, 2574, 3151, 3198, 3312, 3659, 3709,
3725, 4172, 4542, 4860, 4900, 5068, 5220,
5260, 5339, 5442, 5529, 5773, 6128, 6165,
6177, 6269, 6275, 6460, 7167, 7361, 7361,
8051, 8222, 8305, 8992, 9104, 9439, 9844,
10045, 10764, 10787, 11104, 11478, 11508,
11684, 12490, 12590, 12794, 12803, 13823,
13982), type = c("X", "X", "Y", "A", "A",
"B", "X", "X", "X", "B", "B", "A", "A", "A", "B", "B", "X",
"B", "Y", "X", "X", "Y", "Y", "C", "A", "X", "X", "Z", "Z",
"B", "X", "X", "A", "A", "Y", "X", "A", "X", "X", "Z", "Z",
"C", "X", "Y", "Y", "Z", "Z", "Z", "Z", "Z"), y_axis = c(50, 55,
54, 58, 57, 46, 50, 55, 46, 42, 56, 55, 55, 45, 52, 51, 45, 48, 50,
49, 53, 55, 45, 40, 49, 37, 52, 58, 52, 4, 58, 52, 49, 58, 50, 55,
56, 53, 58, 43, 55, 55, 44, 52, 59, 49, 53, 39, 60, 52)