Get correlation value in a tidy way — get

Determine the Pearson correlation coefficient between two variables in a data frame using pipeable and formula-friendly syntax

Usage

get_correlation(data, formula, na.rm = FALSE, ...)

Arguments

data: a data frame object
formula: a formula with the response variable name on the left and the explanatory variable name on the right
na.rm: a logical value indicating whether NA values should be stripped before the computation proceeds.
...: further arguments passed to stats::cor()

Value

A 1x1 data frame storing the correlation value

Examples

library(moderndive)

# Compute correlation between mpg and cyl:
mtcars %>%
  get_correlation(formula = mpg ~ cyl)
#>         cor
#> 1 -0.852162

# Group by one variable:
library(dplyr)
mtcars %>%
  group_by(am) %>%
  get_correlation(formula = mpg ~ cyl)
#> # A tibble: 2 × 2
#>      am    cor
#>   <dbl>  <dbl>
#> 1     0 -0.796
#> 2     1 -0.826

# Group by two variables:
mtcars %>%
  group_by(am, gear) %>%
  get_correlation(formula = mpg ~ cyl)
#> # A tibble: 4 × 3
#> # Groups:   am [2]
#>      am  gear    cor
#>   <dbl> <dbl>  <dbl>
#> 1     0     3 -0.645
#> 2     0     4 -0.959
#> 3     1     4 -0.601
#> 4     1     5 -0.961