如何找出列表中出现次数最多的范围

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"))

样本数据，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

从这个表中，我只想找到最常出现的发动机转速和车速或最常出现的范围。

Answer 1

要查找最常见（模式）的车速，您可以从table 中获取此信息

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

modeSpeed
[1] 4.85

要获得这样一个速度范围内的值，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 接受一个数字变量并根据第二个（中断）参数返回一个因子变量。您可以提供带有表示中断数的单个数字或表示唯一切割点的向量的中断。我包括-Inf 和Inf 以确保全面覆盖。

Answer 2

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 

或者对于几列：

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 

只获取最发生的：

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

$Engine_speed
650 
  2 

$Engine_torq
11 
 1 

这能解决问题吗？