How to find the highest value in a data frame?

Question

I have a dataframe x with these values:

  x1 x2 x3 1 NA 4 1 2 NA 3 NA 3 4 NA 2 4 NA 1 11 5 NA 2 NA 6 5 NA 1 7 5 9 NA 8 NA 2 NA 

A simple question: How to get the maximum value? (eleven)

Answer 1

Use max() with the na.rm argument set to TRUE :

 dat <- read.table(text=" x1 x2 x3 1 NA 4 1 2 NA 3 NA 3 4 NA 2 4 NA 1 11 5 NA 2 NA 6 5 NA 1 7 5 9 NA 8 NA 2 NA", header=TRUE) 

Get the maximum:

 max(dat, na.rm=TRUE) [1] 11 

Answer 2

To find the amount of a column, you can first block it,

 max(unlist(myDataFrame$myColumn), na.rm = TRUE) 

A source

Answer 3

you can write max column function, colMax .

 colMax <- function(data) sapply(data, max, na.rm = TRUE) 

Use the colMax function for sample data:

 colMax(x) # x1 x2 x3 # 5.0 9.0 11.0