R Mean, Median & Mode - r - learn r - r programming
- R uses many in-built functions to perform Statistical analysis in R is performed by using many in-built functions.
- Most of these functions are part of the R base package.
- These functions take R vector as an input along with the arguments and give the result.
- Here we discussing mean, median and mode.
Mean
- It is calculated by taking the sum of the values and dividing with the number of values in a data series.
- The function mean() is used to calculate this in R.
Syntax
- The basic syntax for calculating mean in R is
mean(x, trim = 0, na.rm = FALSE, ...)
- x is the input vector.
- trim is used to drop some observations from both end of the sorted vector.
- na.rm is used to remove the missing values from the input vector.
r programming median
Example
# Create a vector.
x <- c(12,7,3,4.2,18,2,54,-21,8,-5)
# Find Mean.
result.mean <- mean(x)
print(result.mean)
- When we execute the above code, it produces the following result
[1] 8.22
Applying Trim Option
- When trim parameter is supplied, the values in the vector get sorted and then the required numbers of observations are dropped from calculating the mean.
- When trim = 0.3, 3 values from each end will be dropped from the calculations to find mean.
- In this case the sorted vector is (−21, −5, 2, 3, 4.2, 7, 8, 12, 18, 54) and the values removed from the vector for calculating mean are (−21,−5,2) from left and (12,18,54) from right.
# Create a vector.
x <- c(12,7,3,4.2,18,2,54,-21,8,-5)
# Find Mean.
result.mean <- mean(x,trim = 0.3)
print(result.mean)
- When we execute the above code, it produces the following result
[1] 5.55
Applying NA Option
- If there are missing values, then the mean function returns NA.
- To drop the missing values from the calculation use na.rm = TRUE. which means remove the NA values.
# Create a vector.
x <- c(12,7,3,4.2,18,2,54,-21,8,-5,NA)
# Find mean.
result.mean <- mean(x)
print(result.mean)
# Find mean dropping NA values.
result.mean <- mean(x,na.rm = TRUE)
print(result.mean)
- When we execute the above code, it produces the following result
[1] NA
[1] 8.22
Median
- The middle most value in a data series is called the median. The median()function is used in R to calculate this value.
Syntax
- The basic syntax for calculating median in R is
median(x, na.rm = FALSE)
- x is the input vector.
- na.rm is used to remove the missing values from the input vector.
Example
# Create the vector.
x <- c(12,7,3,4.2,18,2,54,-21,8,-5)
# Find the median.
median.result <- median(x)
print(median.result)
- When we execute the above code, it produces the following result
[1] 5.6
Mode
- The mode is the value that has highest number of occurrences in a set of data.
- Unike mean and median, mode can have both numeric and character data.
- R does not have a standard in-built function to calculate mode. So we create a user function to calculate mode of a data set in R.
- This function takes the vector as input and gives the mode value as output.
Example
# Create the function.
getmode <- function(v) {
uniqv <- unique(v)
uniqv[which.max(tabulate(match(v, uniqv)))]
}
# Create the vector with numbers.
v <- c(2,1,2,3,1,2,3,4,1,5,5,3,2,3)
# Calculate the mode using the user function.
result <- getmode(v)
print(result)
# Create the vector with characters.
charv <- c("o","it","the","it","it")
# Calculate the mode using the user function.
result <- getmode(charv)
print(result)
- When we execute the above code, it produces the following result
[1] 2
[1] "it"