ggplot2：为一个变量在右侧创建第二个y轴 [英] ggplot2: Create second y-axis on the right side for one variable
问题描述
我在同一时间范围内有一个包含3个不同变量的数据框。前两个变量具有相同的比例（股票指数值），可以用y轴来说明。第三个变量是利率，范围只有0到7％，所以我专注于在图的右侧创建一个附加的y轴来说明它。但经过2天的尝试和失败，我在您的社区寻求建议。我第一次试图分开我的数据集，并用于 par（new = T）覆盖我的第一个图，但这导致了比以前更多的困难。我已经找到了人们寻找类似问题的案例，但是他们的问题是用我的一些技巧来复制的。
library （reshape2）
library（scales）
library（ggplot2）
df < - data.frame（变量，日期）
df < - melt（df ，id.vars =Dates）
ggplot（df，aes（x = Dates，y = value，fill = variable，color = variable））+ geom_line（stat ='identity'，size = 0.5）+
scale_x_date（breaks = date_breaks（3 months），labels = date_format（％b-％y））+
labs（x =Date，y =MSCI值）+
theme_classic（）+
theme（axis.text.x = element_text（angle = 90，hjust = 1，vjust = 0.5））+
scale_color_manual（values = c（ grey0，orangered2，royalblue2））
）来复制我的情节，并说明我的意思。
Dates < - 结构
9039,9070,9100,9131,9162,9190,9221,9251,9282,9312,9343
9374,9404,9435,9465,9496,9527,9556,9587,9617,9648） （c（1405.713,1498.661,1479.508,1415.972,1459.993，
1464.001,1460.193,1488.212,1533.288,1493.268） ，1536.017,1469.67，
1484.177，1462.17，1483.771,1555.59,1610.111,1624.192,1624.007，
1705.582,1667.891,1716.796,1690.085,1749.089,1800.553,1833.446，$ b $ 1844.949,1875.988,1920.44 ，1922.445,3.05,3.25,3.34,3.56，
4.01,4.25,4.26,4.47,4.73,4.76,5.29,5.45,5.53,5.92,5.98，
6.05,6.01,5.85,5.74 ，5.8,5.76,5.8,5.6,5.56,5.22,5.31，
5.22,5.24,5.27,1226.99191666667,1240.457375，1253.96166666667，
1267.07825,1281.38133333333,1293.99208333333,1308.05641666667，
1323.16016666667,1338.992625 ，1353.58925,1371.2485,1 385.3055，
1399.57704166667，1412.76375，1425.710875，1438.80775，1451.77004166667，
1464.062625，1476.80325，1491.8025，1502.652，1516.61345833333，
1527.86608333333，1544.914875，1561.36654166667，1575.31591666667，
1590.542625，1609.70995833333， 1628.89525,1647.99708333333），.Dim = c（30L，
3L），.Dimnames = list（NULL，c（MSCI.WORLD，Funds.Target.Rate，
Mean.Rolling ）））
变量Funds.Target.Rate应该以更方便的方式呈现。是否有可能在图的右侧创建第二个y轴来表示这个变量的利率？感谢您的时间和帮助。
据我所知，这是ggplot2中不可能的，原因很多。请参阅
I have a dataframe with 3 different variables for the same time horizon. The first two variables have the same scaling (stock indice values) and can be illustrated with the y-axis. The third variable is an interest rate and ranges only from 0 to 7%, so that I focused on creating an additional y-axis on the right hand side of the plot to illustrate it. But after now 2 days trying and failing, I look for advice in your community. I first tried to separate my dataset and used to par(new=T) "overwrite" my first plot, but that led to more difficulties than before. I already found cases where people looked for a similar problem, but their questions were to special to replicate with my few skills.
library(reshape2)
library (scales)
library (ggplot2)
df <- data.frame(Variables, Dates)
df <- melt(df, id.vars="Dates")
ggplot(df, aes(x=Dates, y=value, fill=variable, colour=variable))+geom_line(stat='identity', size=0.5)+
scale_x_date(breaks = date_breaks("3 months"), labels = date_format("%b-%y"))+
labs(x="Date", y="MSCI Value" )+
theme_classic()+
theme(axis.text.x=element_text(angle=90,hjust=1,vjust=0.5))+
scale_color_manual(values=c("grey0", "orangered2", "royalblue2"))
Here some data (the first 30 observations) to replicate my plot and to illustrate what I mean.
Dates <- structure(c(8766, 8797, 8825, 8856, 8886, 8917, 8947, 8978, 9009,
9039, 9070, 9100, 9131, 9162, 9190, 9221, 9251, 9282, 9312, 9343,
9374, 9404, 9435, 9465, 9496, 9527, 9556, 9587, 9617, 9648), class = "Date")
Variables <- structure(c(1405.713, 1498.661, 1479.508, 1415.972, 1459.993,
1464.001, 1460.193, 1488.212, 1533.288, 1493.268, 1536.017, 1469.67,
1484.177, 1462.17, 1483.771, 1555.59, 1610.111, 1624.192, 1624.007,
1705.582, 1667.891, 1716.796, 1690.085, 1749.089, 1800.553, 1833.446,
1844.949, 1875.988, 1920.44, 1922.445, 3.05, 3.25, 3.34, 3.56,
4.01, 4.25, 4.26, 4.47, 4.73, 4.76, 5.29, 5.45, 5.53, 5.92, 5.98,
6.05, 6.01, 6, 5.85, 5.74, 5.8, 5.76, 5.8, 5.6, 5.56, 5.22, 5.31,
5.22, 5.24, 5.27, 1226.99191666667, 1240.457375, 1253.96166666667,
1267.07825, 1281.38133333333, 1293.99208333333, 1308.05641666667,
1323.16016666667, 1338.992625, 1353.58925, 1371.2485, 1385.3055,
1399.57704166667, 1412.76375, 1425.710875, 1438.80775, 1451.77004166667,
1464.062625, 1476.80325, 1491.8025, 1502.652, 1516.61345833333,
1527.86608333333, 1544.914875, 1561.36654166667, 1575.31591666667,
1590.542625, 1609.70995833333, 1628.89525, 1647.99708333333), .Dim = c(30L,
3L), .Dimnames = list(NULL, c("MSCI.WORLD", "Funds.Target.Rate",
"Mean.Rolling")))
The variable "Funds.Target.Rate" should be presented in a more convenient way. Is it possible to create a second y-axis on the right side of the plot that refers to the interest rates of this variable? Thank you for your time and help.
As far as I know, this is not possible in ggplot2, for good reasons. see this discussion. The only thing possible is to add a second axis which is a re-calculation of the first axis, e.g. Celsius -> Fahrenheit or local differences:
ggplot(mpg, aes(displ, hwy)) +
geom_point() +
scale_y_continuous(
"mpg (US)",
sec.axis = sec_axis(~ . * 1.20, name = "mpg (UK)")
)
Having said that, you can use that hack for your purposes. First scale the interest rate, so that all variables have the same dimension (1000 - 2000 in your case) - I multiply Interest.Rate by 400. Then add the second axis and make sure the annotations show the unscaled (i.e. divided) values (* 300 and / 300 in your case):
Variables[, 2] <- Variables[, 2] * 300
df <- data.frame(Variables, Dates)
df <- melt(df, id.vars="Dates")
ggplot(df, aes(x=Dates, y=value, fill=variable, colour=variable))+geom_line(stat='identity', size=0.5)+
scale_x_date(breaks = date_breaks("3 months"), labels = date_format("%b-%y"))+
labs(x="Date", y="MSCI Value" )+
theme_classic()+
theme(axis.text.x=element_text(angle=90,hjust=1,vjust=0.5))+
scale_color_manual(values=c("grey0", "orangered2", "royalblue2")) +
# NEW CODE:
scale_y_continuous("MSCI Value", sec.axis = sec_axis(~ . /300, name = "Interest Rate")
)
这篇关于ggplot2：为一个变量在右侧创建第二个y轴的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
