min for each row with dataframe in R

Question

I\'m try to do a simple minimum across multiple columns in a data frame but the min function automatically returns the min across the whole of each column rather than for ea

Answer 1

You can use apply to go through each row

apply(df, 1, FUN=min)

Where 1 means to apply FUN to each row of df, 2 would mean to apply FUN to columns.

Answer 2

We could use pmin, which finds the parallel minima of sets of values. Since our df is technically a list, we will need to run it via do.call.

df$min <- do.call(pmin, df)

which gives

df
#   x y min
# 1 1 1   1
# 2 2 5   2
# 3 7 4   4

Data:

df <- data.frame(x = c(1, 2, 7), y = c(1, 5, 4))

Furthermore, if na.rm = TRUE is needed, you can do

df$min <- do.call(pmin, c(df, na.rm = TRUE))

Answer 3

We could also use rowMins from library(matrixStats)

library(matrixStats)
df$minIwant <- rowMins(as.matrix(df))

Answer 4

Just want to add on how you can also do this with dplyr.

library(dplyr)

x<-c(1,2,7)
y<-c(1,5,4)
df <- data.frame(x,y)

df %>% rowwise() %>% mutate(minIget = min(x, y))
# A tibble: 3 x 3
    x     y   minIget
  <dbl> <dbl>   <dbl>
1    1.    1.      1.
2    2.    5.      2.
3    7.    4.      4.