Question

我在R中绘制了一个图表：

OBD=read.csv("OBD.CSV",header = TRUE,stringsAsFactors=FALSE)
x1 <- OBD$Time1
x2 <- OBD$Time2
y1<-OBD$Vehicle_speed
y2 <-OBD$Engine_speed
par(mar=c(5,4,4,5)+.1)
plot(x1,y1,type="l",col="yellow",ylab = "Vehicle speed")
par(new=TRUE)
plot(x2,y2,type="l",col="blue4",xaxt="n",yaxt="n",xlab="Time",ylab="")
axis(4)
mtext("Engine speed",side=4,line=3)
legend("topleft",col=c("blue4","yellow"),lty=1,legend=c("y1","y2"))

示例数据，CSV格式：

Vehicle_speed,Time1,Engine_speed,Time2,Engine_torq,Time3,Acc_pedal,Time4,Eng_fuel_rate,Time5
4.98,0,650,0,11,0,0,0,1.15,0
4.98,0,650,0,11,0,0,0,1.2,0.002
4.96,0,650,0.001,11,0.001,0,0.001,1.2,0.003
4.96,0,651,0.001,11,0.001,0,0.001,1.2,0.005
4.94,0.001,651,0.001,11,0.001,0,0.001,1.2,0.007
4.94,0.001,651,0.001,11,0.001,0,0.002,1.2,0.008
4.91,0.001,650.5,0.001,11,0.001,0,0.002,1.2,0.01
4.91,0.001,650.5,0.001,11,0.001,0,0.002,1.2,0.012
4.89,0.001,650.5,0.002,11,0.002,0,0.003,1.15,0.013
4.89,0.001,650.5,0.002,11,0.002,0,0.003,1.15,0.015
4.87,0.002,649.5,0.002,11,0.002,0,0.003,1.15,0.017
4.87,0.002,649.5,0.002,11,0.002,0,0.004,1.15,0.018
4.85,0.002,650,0.002,11,0.002,0,0.004,1.15,0.02
4.85,0.002,650,0.002,11,0.002,0,0.004,1.15,0.022
4.82,0.002,650,0.003,11,0.003,0,0.005,1.2,0.023

从这张表中，我只想找到最发生的发动机转速和车速或大多数发生范围。

Answer 1

OBD <- read.csv(text = "Vehicle_speed,Time1,Engine_speed,Time2,Engine_torq,Time3,Acc_pedal,Time4,Eng_fuel_rate,Time5
         4.98,0,650,0,11,0,0,0,1.15,0
         4.98,0,650,0,11,0,0,0,1.2,0.002
         4.96,0,650,0.001,11,0.001,0,0.001,1.2,0.003
         4.96,0,651,0.001,11,0.001,0,0.001,1.2,0.005
         4.94,0.001,651,0.001,11,0.001,0,0.001,1.2,0.007
         4.94,0.001,651,0.001,11,0.001,0,0.002,1.2,0.008
         4.91,0.001,650.5,0.001,11,0.001,0,0.002,1.2,0.01
         4.91,0.001,650.5,0.001,11,0.001,0,0.002,1.2,0.012
         4.89,0.001,650.5,0.002,11,0.002,0,0.003,1.15,0.013
         4.89,0.001,650.5,0.002,11,0.002,0,0.003,1.15,0.015
         4.87,0.002,649.5,0.002,11,0.002,0,0.003,1.15,0.017
         4.87,0.002,649.5,0.002,11,0.002,0,0.004,1.15,0.018
         4.85,0.002,650,0.002,11,0.002,0,0.004,1.15,0.02
         4.85,0.002,650,0.002,11,0.002,0,0.004,1.15,0.022
         4.82,0.002,650,0.003,11,0.003,0,0.005,1.2,0.023")

> table(OBD$Engine_speed)

649.5   650 650.5   651 
    2     6     4     3

或者有几列：

tables <- apply(OBD[ ,c(1,3,5)], 2, table)

    > tables
$Vehicle_speed

4.82 4.85 4.87 4.89 4.91 4.94 4.96 4.98 
   1    2    2    2    2    2    2    2 

$Engine_speed

649.5   650 650.5   651 
    2     6     4     3 

$Engine_torq

11 
15

只获得最多出现的内容：

> lapply(tables, which.max)
$Vehicle_speed
4.85 
   2 

$Engine_speed
650 
  2 

$Engine_torq
11 
 1

这是否解决了这个问题？

Answer 2

要查找最常见的（模式）车速，您可以从table

中取出

mySpeeds <- table(df$Vehicle_speed)
modeSpeed <- as.numeric(names(mySpeeds)[which.max(mySpeeds)])

modeSpeed
[1] 4.85

要获得一系列速度的这样的值，您应该使用cut：

# get range categories
df$speedRange <- cut(df$Vehicle_speed, breaks=c(-Inf, 4.85, 4.90, 4.95, Inf))

mySpeedsRange <- table(df$speedRange)
modeSpeedRange <- names(mySpeedsRange)[which.max(mySpeedsRange)]

modeSpeedRange
[1] "(4.85,4.9]"

cut接受一个数值变量，并根据第二个（break）参数返回一个因子变量。您可以提供具有单个数字的中断，指示中断的数量或向量，指示唯一的切割点。我添加了-Inf和Inf以确保完全覆盖。

如何找出列表中最常出现的范围

2 个答案: