How to restore the default format of a correlation table in the model summary package of R after adding p values with a custom function

Question

This is a follow-up question to a recent post about how to add p-values to a correlation table.

How to add a p-value to a correlation table while using model summary package in r?

The solution proposed by Vincent (reproduced below) is to use a custom function for the method argument.

library(modelsummary)
library(correlation)

dat = mtcars[1:5, 1:5]

fun = function(x) {
    out = correlation(x)
    stars = c("*" = .2, "**" = .15, "***" = .05)
    p = modelsummary:::make_stars(out$p, stars)
    out$r = sprintf("%.2f%s", out$r, p)
    out = as.matrix(out)
    return(out)
}

datasummary_correlation(dat, method = fun)

The custom function solves the p-value issue however I now get a full rectangular correlation table showing all values whereas before adding the custom function I got only the lower triangle values by default (which is what I want). datasummary_correlation(dat) produces a lower-triangle correlation table using default arguments (but it doesn't have p-values).

Modelsummary documentation linked below indicates that inserting datasummary_correlation_format() in the custom function will allow me to restore the default settings.

https://vincentarelbundock.github.io/modelsummary/reference/datasummary_correlation_format.html

But I can't get it to work.

Here is my attempt

library(modelsummary)
library(correlation)

dat = mtcars[1:5, 1:5]

fun = function(x) {
    out = correlation(x)
  
 datasummary_correlation_format(
    out,
    fmt = 2,
    upper_triangle = ".",
    diagonal = "1")

    stars = c("*" = .2, "**" = .15, "***" = .05)
    p = modelsummary:::make_stars(out$p, stars)
    out$r = sprintf("%.2f%s", out$r, p)
    out = as.matrix(out)
    return(out)
}

datasummary_correlation(dat, method = fun)

Answer 1

Try:

library(modelsummary)
library(correlation)

dat = mtcars[, 1:5]

fun = function(x) {
    out = correlation(x)
    stars = c("*" = .2, "**" = .15, "***" = .05)
    p = modelsummary:::make_stars(out$p, stars)
    out$r = sprintf("%.2f%s", out$r, p)
    out = as.matrix(out)
    out = datasummary_correlation_format(out, fmt = 2, upper_triangle = ".")
    return(out)
}

datasummary_correlation(dat, method = fun)

	mpg	cyl	disp	hp	drat
mpg	1	.	.	.	.
cyl	-.85***	1	.	.	.
disp	-.85***	.90***	1	.	.
hp	-.78***	.83***	.79***	1	.
drat	.68***	-.70***	-.71***	-.45***	1