subset columns in r code example

Example 1: subset row r

# df[row,column]

df[1, ]   # select first row and all columns from df
df[ ,8]   # select all rows for column 8 from df
df[2,5]   # select row 2, column 5 from df 
df[1:5, ] # select rows 1 to 5 and all columns from df

Example 2: reorder columns in r

col_order <- c("Species", "Petal.Width", "Sepal.Length",
               "Sepal.Width", "Petal.Length")
my_data2 <- my_data[, col_order]
my_data2

# or
my_data2 <- my_data[, c(5, 4, 1, 2, 3)]