move some code out of find_similar_colour()

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: ibawds
 Type: Package
 Title: Functions and Datasets for the Data Science Course at IBAW
-Version: 0.6.0.9001
+Version: 0.6.0.9002
 Author: Stefan Lanz
 Maintainer: Stefan Lanz <slanz1137@gmail.com>
 Description: A collection of useful functions and datasets for the Data Science

R/find_similar_colour.R

@@ -65,12 +65,7 @@ find_similar_colour <- function(colour,
   cols_rgb <- grDevices::col2rgb(cols)
 
   # compute the distances and find the most similar colour
-  if (distance == "euclidean") {
-    dist <- apply(cols_rgb, 2, function(x) sum((x - col_rgb)^2))
-  } else {
-    dist <- apply(cols_rgb, 2, function(x) sum(abs(x - col_rgb)))
-  }
-  i_min <- which.min(dist)
+  i_min <- which_min_dist(col_rgb, cols_rgb, distance)
   sim_col <- cols[i_min]
 
   if (verbose) {
@@ -84,3 +79,16 @@ find_similar_colour <- function(colour,
   sim_col
 
 }
+
+
+# compute the distance between x and each value of y
+
+which_min_dist <- function(x, y, method) {
+  dist_fun <- if (method == "euclidean") {
+    function(z) sum((x - z)^2)
+  } else {
+    function(z) sum(abs(x - z))
+  }
+  apply(y, 2, dist_fun) %>%
+    which.min()
+}