Calculate the Max in R

Your goal

You need to calculate the maximum value of a numerical dataset in R.

Step-by-step tutorial

Use the max function from the base package. The specific approach depends on the data representation, as we illustrate below.

Vector data

Use max to get the maximum value in a vector:

> max(c(4, 5, 6, 2, 8, 8, 4))
[1] 8

You can also use the range function to get the minimum and maximum in a single shot:

> range(c(4, 5, 6, 2, 8, 8, 4))
[1] 2 8

Data frame

> precip.df <- read.csv("precip-central-park.csv")
> head(precip.df)
  YEAR  JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC ANNUAL
1 1869 2.53 6.87 4.61 1.39 4.15 4.40 3.20 1.76 2.81 6.48 2.03 5.02  45.25
2 1870 4.41 2.83 3.33 5.11 1.83 2.82 3.76 3.07 2.52 4.97 2.42 2.18  39.25
3 1871 2.07 2.72 5.54 3.03 4.04 7.05 5.57 5.60 2.34 7.50 3.56 2.24  51.26
4 1872 1.88 1.29 3.74 2.29 2.68 2.93 7.83 6.29 2.95 3.35 4.08 3.18  42.49
5 1873 5.34 3.80 2.09 4.16 3.69 1.28 4.61 9.56 3.14 2.73 4.63 2.96  47.99
6 1874 5.33 2.04 2.12 8.77 2.24 2.78 5.06 2.43 8.24 1.70 2.30 2.82  45.83
> max(precip.df[, "JUL"])
[1] 11.89

As above, you can use range to get the minimum and maximum together:

> range(precip.df[, "JUL"])
[1]  0.44 11.89

Tibble

> library(readr)
> precip.tbl <- read_csv("precip-central-park.csv")
Parsed with column specification:
cols(
  YEAR = col_double(),
  JAN = col_double(),
  FEB = col_double(),
  MAR = col_double(),
  APR = col_double(),
  MAY = col_double(),
  JUN = col_double(),
  JUL = col_double(),
  AUG = col_double(),
  SEP = col_double(),
  OCT = col_double(),
  NOV = col_double(),
  DEC = col_double(),
  ANNUAL = col_double()
)
> max(precip.tbl[, "JUL"])
[1] 11.89

As before, you can use range to get the minimum and maximum together:

7gt; range(precip.tbl[, "JUL"])
[1]  0.44 11.89