计算数据框中所有非数字列的模式

Question

I would like to calculate the mode of each column from a dataframe. I have found similar posts on how to determine the mode of a vector of rows in a dataframe (but most have been with numeric data).

df <- data.frame(c("A","B","C","C"), c("A","A","B","C"),c("A","B","B","C"))
colnames(df) <- c("V1","V2","V3")
rownames(df) <- c(1,2,3,4)
df

I am using the following function:

modefunc <- function(x){
    tabresult <- tabulate(x)
    themode <- which(tabresult == max(tabresult))
    if(sum(tabresult == max(tabresult))>1) themode <- NA
    return(themode)
}

mode.vector <- apply(df, 1, modefunc)

Since my dataframe is not numeric, I unfortunately get the following error:

Error in tabulate(x) : 'bin' must be numeric or a factor

Any assistance with this would be helpful. Thanks in advance.

Answer 1

I changed your function a little.

modefunc <- function(x){
  x<-c(as.character(x) ,use.names = F,  recursive = TRUE )
  tabresult <- table(x)
  mod<-sort(table(x),decreasing = T)[1]
  mod_name<-names(mod)
  if(sum(tabresult == mod)>1) themode <- NA
  return(mod_name)
}

mode.vector <- apply(df, 1, modefunc)
 1   2   3   4 
"A" "B" "B" "C"