In this tutorial you will learn how to use range function in R. In R programming language range function is used for several practical implementations that require analysis of data using statistical and graph functions. You will also learn how to use range function with NA values and Inf values on vector or dataframe.
Statistically, a range of a data set is defined as the difference between maximum and minimum values i.e ( max_value - min_value).
In R programming, a range () function is defined as the interval between the largest (maximum) and smallest (minimum) data value within a vector or column in a data frame in R.
Although the definitions appear to be identical, the range function in R programming differs in a way that it only returns the two extremes rather than the difference value. So a range() in R is suitable for the following:-
A range() function in R source code is declared by using the following syntax.
range(x,na.rm = FALSE)
Where
Let us begin with simple practical examples for better understanding. First, create a vector x of numeric data type which holds a set of values.
#Created a vector of numeric data type using c()
x = c(24,5,6,7,7,-1,0)
cat("The numeric vector x is :",x,"\n")
The R code after execution returns a vector x as
The numeric vector x is : 24 5 6 7 7 -1 0
Now by applying the range() function in vector x you can find the maximum(24) and minimum(-1)values from the vector x.
range(x)
The lowest and highest values are returned in x.
[1] -1 24
NA is a reserved word that indicates the value is not available or missing ie “ Not Available (NA)” We need to change the syntax by adding a parameter na.rm to the range() whose value can be either TRUE or FALSE. In case NA is present in an input vector or data structure the range function fails to return the result. So na.rm assigned to TRUE will remove the NA present in input while finding the range() function and providing the accurate result.
Consider the same vector x with NA occupied among a given set of values together with Inf which is another reserved word in R to show infinity.
x = c(24,5,Inf,6,7,7,-1,0,NA)
Applying range(x) we get
[1] NA NA
From the output, it is clearly visible that the input with NA is not evaluated by a range(). Here we go with the modified syntax for removing NA.
range(x,na.rm=TRUE)
The output after addition of na.rm=TRUE inside range() returns lowest value(-1) and highest value(Inf),which excludes the NA among the vector values.;
[1] -1 Inf
Let us begin by creating a data frame with a few items of different categories and find out the lowest and highest item in terms of their price.
items = data.frame(ITEMS = c("Fruit","Fruit","Fruit","Fruit","Fruit","Vegetable","Vegetable","Vegetable","Vegetable","Dairy","Dairy","Dairy","Dairy","Dairy"),
ITEM_NAME = c("Apple","Banana","Orange","Mango","Papaya","Carrot","Potato","Brinjal","Raddish","Milk","Curd","Cheese","Milk","Paneer"),
PRICE = c(100.981,80.643,80.223,90.3,65.3,71.9,62.2,71.3,25.1,62.9,41.9,35.7,50.9,121.7))
items
The output items data frame is
ITEMS ITEM_NAME PRICE 1 Fruit Apple 100.981 2 Fruit Banana 80.643 3 Fruit Orange 80.223 4 Fruit Mango 90.300 5 Fruit Papaya 65.300 6 Vegetable Carrot 71.900 7 Vegetable Potato 62.200 8 Vegetable Brinjal 71.300 9 Vegetable Raddish 25.100 10 Dairy Milk 62.900 11 Dairy Curd 41.900 12 Dairy Cheese 35.700 13 Dairy Milk 50.900 14 Dairy Paneer 121.700
By applying the range function over the data frame items, we get maximum and minimum values.
range(items$PRICE)
[1] 25.1 121.7
The range in the R programming language can also be determined using min() and max() functions. The min() function finds the minimum data value in the input vector or datatype. The max() function finds the maximum data value from the given input.
min(<vector>,na.rm=TRUE) #To find minimum
max(<vector>,na.rm=TRUE) #To find maximum
A simple program using min() and max() in R where na.rm is to exclude if NA is present. A vector x of numeric data type is created using c() and returns Inf for max() and -1 for min() functions.
x = c(24,5,Inf,6,7,7,-1,0,NA)
> print(max(x,na.rm=TRUE))
[1] Inf
> print(min(x, na.rm=TRUE))
[1] -1
The range of an observation can be calculated by finding the difference between the highest and lowest values. The same theory is applicable to finding the range of a vector or data frame from its given inputs.
Range = max(<vector>,na.rm=TRUE)- min(<vector>,na.rm=TRUE)
Program to find range using min() and max()
#Created a vector of numeric data type using c()
x = c(24,5,4,6,7,7,-1,0,NA)
print(x)
# find range
print(max(x, na.rm=TRUE)-min(x, na.rm=TRUE))
The output of the R source code is
[1] 24 5 4 6 7 7 -1 0 NA [1] 25
The range in column data frames can also be determined using maximum(max) and minimum(min) functions as we do with vectors. The highest value in any particular column of the data frame can be obtained using the max() function. The lowest value of the column in the data frame can be obtained using the min() function. In both cases, the NA values can be excluded using na.rm=TRUE.
max(dataframe$column_name,na.rm=TRUE)-min(dataframe$column_name,na.rm=TRUE)
Program to find the range in a data frame.
# create dataframe
x = data.frame(first=c(98, 5, 67, 67, 23, 45, 78, NA, 89), sec 41, 96, 34, 27, 23, NA, 73,NA))
# display
print(x)
The above R code creates a data frame using two columns named “first” and “second”. Let us find the range of two columns.
# find range in column1
print(max(x$first, na.rm=TRUE)-min(x$first, na.rm=TRUE))
# find range in column2
print(max(x$second, na.rm=TRUE)-min(x$second, na.rm=TRUE))
The execution of the above code displays
[1] 93 [1] 73
The entire data frame range is obtained by finding the difference between maximum and minimum values present which is further determined using max() and min() functions.
max(dataframe,na.rm=TRUE)-min(dataframe,na.rm=TRUE)
Program to find the entire range in a data frame
# create dataframe
x = data.frame(first=c(98, 5, 67, 67, 23, 45, 78, NA, 89), sec 41, 96, 34, 27, 23, NA, 73,NA))
# display
print(x)
# find range in entire dataframe
print(max(x, na.rm=TRUE)-min(x, na.rm=TRUE))
[1] 93
