Make vis_cor have a consistent legend between -1 and 1

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: visdat
 Title: Preliminary Visualisation of Data
-Version: 0.5.2.9001
+Version: 0.5.3.9000
 Authors@R: c(
   person("Nicholas", "Tierney", role = c("aut", "cre"),
       email = "nicholas.tierney@gmail.com", 

NEWS.md

@@ -1,15 +1,12 @@
-# visdat 0.5.2.9001 (2018/12/14)
+# visdat 0.5.3.9000 (2019/02/04)
 
 ## Minor Change
 
+* Update `vis_cor()` to use perceptually uniform colours from `scico` package, using `scico::scico(3, palette = "vik")`.
+* Update `vis_cor()` to have fixed legend values from -1 to +1 (#110) using 
+  options `breaks` and `limits`. Special thanks to [this SO thread for the answer](https://stackoverflow.com/questions/24265652/label-minimum-and-maximum-of-scale-fill-gradient-legend-with-text-ggplot2)
 * Uses `glue` and `glue_collapse()` instead of `paste` and `paste0`
 
-# visdat 0.5.2.9000 (2018/12/12)
-
-## Minor Change
-
-* Version bump to dev version
-
 # visdat 0.5.2 (2018/12/06) "Youth, The Midnight, Kids"
 
 ## Minor Change

R/vis-cor.R

@@ -42,15 +42,19 @@ vis_cor <- function(data,
                                           y = "row_2",
                                           fill = "value")) +
         ggplot2::geom_raster() +
-        ggplot2::scale_fill_gradient2(low = "steelblue",
-                                      mid = "white",
-                                      high = "salmon") +
+      # colours from scico::scico(3, palette = "vik")
+        ggplot2::scale_fill_gradient2(low = "#001260",# blue
+                                      mid = "#EAEDE9", # white
+                                      high = "#601200", # red
+                                      breaks = c(-1, -0.5, 0, 0.5, 1),
+                                      limits = c(-1, 1)) +
         ggplot2::theme_minimal() +
         ggplot2::scale_x_discrete(position = "top") +
         ggplot2::labs(x = "",
                       y = "") +
-        ggplot2::guides(fill = ggplot2::guide_legend(title = "correlation")) +
-        ggplot2::theme(axis.text.x = ggplot2::element_text(angle = 45, hjust = 0))
+        ggplot2::guides(fill = ggplot2::guide_legend(title = "Correlation")) +
+        ggplot2::theme(axis.text.x = ggplot2::element_text(angle = 45,
+                                                           hjust = 0))
   }
   }