cv: Calculate the coefficient of variation

In cmstatr: Statistical Methods for Composite Material Data

Calculate the coefficient of variation

Description

The coefficient of variation (CV) is the ratio of the standard deviation to the mean of a sample. This function takes a vector of data and calculates the CV.

Usage

cv(x, na.rm = FALSE)

Arguments

x	a vector
na.rm	logical. Should missing values be removed?

Value

The calculated CV

Examples

set.seed(15)  # make this example reproducible
x <- rnorm(100, mean = 100, sd = 5)
cv(x)
## [1] 0.04944505

# the cv function can also be used within a call to dplyr::summarise
library(dplyr)
carbon.fabric %>%
filter(test == "WT") %>%
  group_by(condition) %>%
  summarise(mean = mean(strength), cv = cv(strength))

## # A tibble: 3 x 3
##   condition  mean     cv
##   <chr>     <dbl>  <dbl>
## 1 CTD        137. 0.0417
## 2 ETW        135. 0.0310
## 3 RTD        142. 0.0451

cmstatr documentation built on Sept. 9, 2023, 9:06 a.m.