control sizes of intervals and points in mcmc_intervals (#229)

* Add arguments to change interval and point size

Fixes #228
Fixes #215

* add visual test

* Update NEWS.md

Co-authored-by: TJ Mahr <tjmahr@users.noreply.github.com>

NEWS.md

@@ -9,6 +9,8 @@
 -->
 
 * Added missing `facet_args` argument to `mcmc_rank_overlay()`. (#221, @hhau)
+* Size of points and interval lines can set in 
+  `mcmc_intervals(..., outer_size, inner_size, point_size)`. (#215, #228, #229) 
 
 
 # bayesplot 1.7.2

R/mcmc-intervals.R

@@ -25,6 +25,9 @@
 #'   `"equal height"` are scaled using `height*sqrt(height)`
 #' @param point_est The point estimate to show. Either `"median"` (the
 #'   default), `"mean"`, or `"none"`.
+#' @param inner_size,outer_size For `mcmc_intervals()`, the size of
+#'   the inner and interval segments, respectively.
+#' @param point_size For `mcmc_intervals()`, the size of point estimate.
 #' @param rhat An optional numeric vector of R-hat estimates, with one element
 #'   per parameter included in `x`. If `rhat` is provided, the intervals/areas
 #'   and point estimates in the resulting plot are colored based on R-hat value.
@@ -160,6 +163,9 @@ mcmc_intervals <- function(x,
                            prob = 0.5,
                            prob_outer = 0.9,
                            point_est = c("median", "mean", "none"),
+                           outer_size = 0.5,
+                           inner_size = 2,
+                           point_size = 4,
                            rhat = numeric()) {
   check_ignored_arguments(...)
 
@@ -184,17 +190,18 @@ mcmc_intervals <- function(x,
 
   args_outer <- list(
     mapping = aes_(x = ~ ll, xend = ~ hh, y = ~ parameter, yend = ~ parameter),
-    color = get_color("mid")
+    color = get_color("mid"),
+    size = outer_size
   )
   args_inner <- list(
     mapping = aes_(x = ~ l, xend = ~ h, y = ~ parameter, yend = ~ parameter),
-    size = 2,
+    size = inner_size,
     show.legend = FALSE
   )
   args_point <- list(
     mapping = aes_(x = ~ m, y = ~ parameter),
     data = data,
-    size = 4,
+    size = point_size,
     shape = 21
   )
 

tests/testthat/test-mcmc-intervals.R

@@ -197,6 +197,9 @@ test_that("mcmc_intervals renders correctly", {
 
   p_mean_points <- mcmc_intervals(vdiff_dframe, point_est = "mean")
   vdiffr::expect_doppelganger("mcmc_intervals (means)", p_mean_points)
+
+  p_sizes <- mcmc_intervals(vdiff_dframe, point_size = 1, inner_size = 5, outer_size = 4)
+  vdiffr::expect_doppelganger("mcmc_intervals (sizes)", p_sizes)
 })
 
 test_that("mcmc_areas renders correctly", {