使用ifelse对R中的数据进行子集设置

我试图使用ifelse对数据进行子集划分，然后在绘图中使用这些数据。我是这样编码的，因为我试图通过只定义一个或两个对象，然后运行整个脚本，使用给定条件选择的数据生成一个绘图，从而使代码对外行可用

问题是mydataframe[mydataframe$data….]操作的工作方式与我希望它在ifelse中的工作方式不同。有没有办法让它在ifelse中工作？或者有没有人知道一种更聪明的方法来做我想做的事情？谢谢

另外，第二块代码添加了解释，但不需要查看问题

# generate data
mydata<-c(1:100)
mydata<-as.data.frame(mydata)
mydata$checkthefunction<-rep(c("One","Two","Three","Four","Multiple of 5",
                           "Six","Seven","Eight","Nine","Multiple of 10"))
# everything looks right
mydata

# create function
myfunction = function(MyCondition="low"){

  # special criteria
  lowRandomNumbers=c(58,61,64,69,73)
  highRandomNumbers=c(78,82,83,87,90)
  # subset the data based on MyCondition
  mydata<-ifelse(MyCondition=="low",mydata[mydata$mydata %in% lowRandomNumbers==TRUE,],mydata)
  mydata<-ifelse(MyCondition=="high",mydata[mydata$mydata %in% highRandomNumbers==TRUE,],mydata)
  # if not "high" or "low" then don't subset the data

  mydata
}

myfunction("low")
# returns just the numbers selected from the dataframe, not the 
# subsetted dataframe with the $checkthefunction row

myfunction("high")
# returns: "Error in mydata[mydata$mydata %in% highRandomNumbers == TRUE, ] : 
# incorrect number of dimensions"









# additional explanation code if it helps

# define dataframe again
mydata<-c(1:100)
mydata<-as.data.frame(mydata)
mydata$checkthefunction<-rep(c("One","Two","Three","Four","Multiple of 5",
                               "Six","Seven","Eight","Nine","Multiple of 10"))
# outside of the function and ifelse my subsetting works
lowRandomNumbers=c(58,61,64,69,73)
ItWorks<-mydata[mydata$mydata %in% lowRandomNumbers==TRUE,]

# ifelse seems to be the problem, the dataframe is cut into the string of lowRandomNumbers again
MyCondition="low"
NoLuck<-ifelse(MyCondition=="low",mydata[mydata$mydata %in% lowRandomNumbers==TRUE,],mydata)  
NoLuck

# if the 'else' portion is returned the dataframe is converted to a one-dimensional list
MyCondition="high"
NoLuck<-ifelse(MyCondition=="low",mydata[mydata$mydata %in% lowRandomNumber==TRUE,mydata)  
NoLuck               

#生成数据
mydata您不需要
ifelse
。您需要
if
和
else
<如果有条件向量，则使用code>ifelse

。您只有一个条件值

myfunction = function(MyCondition="low"){

  # special criteria
  lowRandomNumbers=c(58,61,64,69,73)
  highRandomNumbers=c(78,82,83,87,90)
  # subset the data based on MyCondition
  mydata <- if(MyCondition=="low") mydata[mydata$mydata %in% lowRandomNumbers==TRUE,] else mydata
  mydata <- if(MyCondition=="high") mydata[mydata$mydata %in% highRandomNumbers==TRUE,] else mydata
  # if not "high" or "low" then don't subset the data

  mydata
}

myfunction=function（MyCondition=“低”）{
#特殊标准
lowRandomNumbers=c（58,61,64,69,73）
高随机数=c（78,82,83,87,90）
#基于MyCondition对数据进行子集划分
mydata您不需要
ifelse
。如果有条件向量，您需要
if
和
else
，
ifelse
。您只有一个条件值

myfunction = function(MyCondition="low"){

  # special criteria
  lowRandomNumbers=c(58,61,64,69,73)
  highRandomNumbers=c(78,82,83,87,90)
  # subset the data based on MyCondition
  mydata <- if(MyCondition=="low") mydata[mydata$mydata %in% lowRandomNumbers==TRUE,] else mydata
  mydata <- if(MyCondition=="high") mydata[mydata$mydata %in% highRandomNumbers==TRUE,] else mydata
  # if not "high" or "low" then don't subset the data

  mydata
}

myfunction=function（MyCondition=“低”）{
#特殊标准
lowRandomNumbers=c（58,61,64,69,73）
高随机数=c（78,82,83,87,90）
#基于MyCondition对数据进行子集划分
我的数据好，这是一个比我预期的更容易的修复，它可以工作。谢谢！@Roland使用if和else，我必须在else中指定，如果不满足任何条件，则不更改数据帧？或者如果不满足“if”条件，R会自动不更改数据帧吗？这是一个比我预期的更容易的修复，它可以工作。谢谢！@Roland使用if和else，我是否必须在else中指定，如果不满足任何条件，则不更改数据帧？或者如果不满足“if”条件，R是否会自动不更改数据帧？