Question

这是我的代码和错误/警告消息

library(dplyr)

df_sw = as.data.frame(starwars)

df_sw = df_sw[1:11]
final = ""
print(mean(df_sw[,1],trim = 0, na.rm = TRUE))
for(i in 1:ncol(df_sw)){
  print("hello")
  cat(colnames(df_sw)[i], ": ",ifelse(is.numeric(df_sw[1,i]),cat("numeric the mean is: ",mean(df_sw[,i],trim = 0, na.rm = TRUE)),"character: "))
  for(b in 1:4){
    cat(df_sw[b,i], " ")
  }
}

[1]“你好” 名称：字符：卢克·天行者C-3PO R2-D2达斯·维达[1]“你好” 数字平均值是：174.358。 ans [ypos] <-rep中的错误（是，length.out = len）[ypos]：替换的长度为零另外：警告消息：在rep（yes，length.out = len）中：'x'为NULL，因此结果为NULL

我对R很陌生。由于某种原因，我的mean（）函数在抛出错误之前仅返回均值的一部分。我尝试写

mean(df_sw[,I], na.rm = TRUE)

在for循环之外，它同时返回NA和错误/警告。

任何帮助将不胜感激

Answer 1

我们可以将ifelse更改为if/else

for(i in seq_along(df_sw)){
   
   # // if the column is numeric
   if(is.numeric(df_sw[,i])) {
   # // print the mean
   cat(colnames(df_sw)[i], ": numeric the mean is: ",
             mean(df_sw[,i],trim = 0, na.rm = TRUE), "\n")
   } else {
    # // print that it is a character column
     cat(colnames(df_sw)[i], ": character: \n")
   
    }
 }

#name : character: 
#height : numeric the mean is:  174.358 
#mass : numeric the mean is:  97.31186 
#hair_color : character: 
#skin_color : character: 
#eye_color : character: 
#birth_year : numeric the mean is:  87.56512 
#sex : character: 
#gender : character: 
#homeworld : character: 
#species : character:

mean（，na.rm = TRUE）返回NA和警告消息

1 个答案: