stretch is a specified implementation of tidyr::gather() to be applied
to a correlation data frame. It will gather the columns into a long-format
data frame. The term column is handled automatically.
stretch(x, na.rm = FALSE, remove.dups = FALSE)cor_df. See correlate.
Boolean. Whether rows with an NA correlation (originally the matrix diagonal) should be dropped? Will automatically be set to TRUE if mirror is FALSE.
Removes duplicate entries, without removing all NAs
tbl with three columns (x and y variables, and their correlation)
x <- correlate(mtcars)
#> Correlation computed with
#> * Method: 'pearson'
#> * Missing treated using: 'pairwise.complete.obs'
stretch(x) # Convert all to long format
#> # A tibble: 121 × 3
#> x y r
#> <chr> <chr> <dbl>
#> 1 mpg mpg NA
#> 2 mpg cyl -0.852
#> 3 mpg disp -0.848
#> 4 mpg hp -0.776
#> 5 mpg drat 0.681
#> 6 mpg wt -0.868
#> 7 mpg qsec 0.419
#> 8 mpg vs 0.664
#> 9 mpg am 0.600
#> 10 mpg gear 0.480
#> # … with 111 more rows
stretch(x, na.rm = TRUE) # omit NAs (diagonal in this case)
#> # A tibble: 110 × 3
#> x y r
#> <chr> <chr> <dbl>
#> 1 mpg cyl -0.852
#> 2 mpg disp -0.848
#> 3 mpg hp -0.776
#> 4 mpg drat 0.681
#> 5 mpg wt -0.868
#> 6 mpg qsec 0.419
#> 7 mpg vs 0.664
#> 8 mpg am 0.600
#> 9 mpg gear 0.480
#> 10 mpg carb -0.551
#> # … with 100 more rows
x <- shave(x) # use shave to set upper triangle to NA and then...
stretch(x, na.rm = TRUE) # omit all NAs, therefore keeping each
#> # A tibble: 55 × 3
#> x y r
#> <chr> <chr> <dbl>
#> 1 mpg cyl -0.852
#> 2 mpg disp -0.848
#> 3 mpg hp -0.776
#> 4 mpg drat 0.681
#> 5 mpg wt -0.868
#> 6 mpg qsec 0.419
#> 7 mpg vs 0.664
#> 8 mpg am 0.600
#> 9 mpg gear 0.480
#> 10 mpg carb -0.551
#> # … with 45 more rows
# correlation only once.