use integers in x-axis breaks for racing autoplot()s (#95)

NEWS.md

@@ -1,5 +1,7 @@
 # finetune (development version)
 
+* `autoplot()` methods for racing objects will now use integers in x-axis breaks (#75).
+
 * Enabling the `verbose_elim` control option for `tune_race_anova()` will now additionally introduce a message confirming that the function is evaluating against the burn-in resamples.
 
 * Updates based on the new version of tune, primarily for survival analysis models. 

R/plot_race.R

@@ -31,7 +31,14 @@ plot_race <- function(x) {
     ggplot2::ggplot(ggplot2::aes(x = stage, y = mean, group = .config, col = .config)) +
     ggplot2::geom_line(alpha = .5, show.legend = FALSE) +
     ggplot2::xlab("Analysis Stage") +
-    ggplot2::ylab(metric)
+    ggplot2::ylab(metric) +
+    ggplot2::scale_x_continuous(breaks = integer_breaks)
+}
+
+integer_breaks <- function(lims) {
+  breaks <- pretty(lims)
+
+  unique(round(breaks))
 }
 
 stage_results <- function(ind, x) {