You can use the min() and max() functions in R to quickly calculate the minimum and maximum values in a vector.
#find minimum value min(x) #find maximum value max(x)
The following examples show how to use these functions in practice.
Example 1: Max & Min of Vector
The following code shows how to find the minimum and maximum values of a vector:
#define vector x <- c(2, 3, 4, 4, 7, 12, 15, 19, 22, 28, 31, 34) #find minimum value min(x) [1] 2 #find maximum value max(x) [1] 34
Note that if you have missing values in the vector, you must specify na.rm=TRUE to ignore missing values when calculating the minimum and maximum:
#define vector with some missing values x <- c(2, 3, 4, 4, NA, 12, NA, 19, 22, 28, 31, 34) #find minimum value min(x, na.rm=TRUE) [1] 2 #find maximum value max(x, na.rm=TRUE) [1] 34
Example 2: Max & Min of Entire Data Frame
The following code shows how to find the minimum and maximum values of an entire data frame:
#define data frame
df <- data.frame(a=c(1, 3, 4, 6, 8, 9),
b=c(7, 8, 8, 7, 13, 16),
c=c(11, 13, 13, 18, 19, 22),
d=c(12, 16, 18, 22, 29, 38))
#find minimum value
min(df)
[1] 1
#find maximum value
max(df)
[1] 38
Example 3: Max & Min of Column in Data Frame
The following code shows how to find the minimum and maximum values of a specific column in a data frame:
#define data frame
df <- data.frame(a=c(1, 3, 4, 6, 8, 9),
b=c(7, 8, 8, 7, 13, 16),
c=c(11, 13, 13, 18, 19, 22),
d=c(12, 16, 18, 22, 29, 38))
#find minimum value of column c
min(df$c)
[1] 11
#find maximum value of column c
max(df$c)
[1] 22
Example 4: Max & Min of Several Columns in Data Frame
The following code shows how to find the minimum and maximum values of several columns in a data frame:
#define data frame
df <- data.frame(a=c(1, 3, 4, 6, 8, 9),
b=c(7, 8, 8, 7, 13, 16),
c=c(11, 13, 13, 18, 19, 22),
d=c(12, 16, 18, 22, 29, 38))
#find minimum value in columns a, b, and d
apply(df[ , c('a', 'b', 'd')], 2, min)
a b d
1 7 12
#find maximum value in columns a, b, and d
apply(df[ , c('a', 'b', 'd')], 2, max)
a b d
9 16 38
Additional Resources
How to Calculate Standard Deviation in R
How to Calculate the Range in R
How to Loop Through Column Names in R