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Compute a correlation matrix and (raw) p-values from raw data

Source: R/compute_correlations.R
compute_correlations.Rd

A thin wrapper around psych::corr.test() that returns the correlation (r) and unadjusted p-value (p) matrices bundled in a single object suitable for passing straight to corr_wheel().

Usage

compute_correlations(
  data,
  vars = NULL,
  method = c("pearson", "spearman", "kendall"),
  use = "pairwise.complete.obs"
)

Arguments

data

A data frame or matrix of observations (rows) by variables (columns).

vars

Optional character vector selecting and ordering the columns of data to use. Defaults to all columns.

method

Correlation method, passed to psych::corr.test(). One of "pearson", "spearman", "kendall".

use

Handling of missing values, passed to psych::corr.test().

Value

An object of class "circlecor": a list with elements r (the correlation matrix), p (a symmetric matrix of raw, unadjusted p-values), n (the pairwise sample sizes from psych), and method.

Details

Multiple-comparison adjustment is deliberately not applied here. On a correlation wheel, self-correlations and (usually) within-category correlations are never tested, so they should not count towards the family of comparisons. corr_wheel() therefore applies the adjustment itself, over exactly the set of correlations it displays – which is both statistically consistent and more powerful than adjusting across the full matrix. See the adjust and hide_within_group arguments of corr_wheel().

See also

corr_wheel()

Examples

cc <- compute_correlations(mtcars, method = "pearson")
str(cc)
#> List of 4
#>  $ r     : num [1:11, 1:11] 1 -0.852 -0.848 -0.776 0.681 ...
#>   ..- attr(*, "dimnames")=List of 2
#>   .. ..$ : chr [1:11] "mpg" "cyl" "disp" "hp" ...
#>   .. ..$ : chr [1:11] "mpg" "cyl" "disp" "hp" ...
#>  $ p     : num [1:11, 1:11] 0.00 6.11e-10 9.38e-10 1.79e-07 1.78e-05 ...
#>   ..- attr(*, "dimnames")=List of 2
#>   .. ..$ : chr [1:11] "mpg" "cyl" "disp" "hp" ...
#>   .. ..$ : chr [1:11] "mpg" "cyl" "disp" "hp" ...
#>  $ n     : num 32
#>  $ method: chr "pearson"
#>  - attr(*, "class")= chr "circlecor"