fix checks & update vignette
diff --git a/R/kableExtra-package.R b/R/kableExtra-package.R
index 0e9df80..2aa3c7b 100644
--- a/R/kableExtra-package.R
+++ b/R/kableExtra-package.R
@@ -69,6 +69,7 @@
 #' @importFrom scales rescale
 #' @importFrom viridisLite viridis
 #' @importFrom stats ave
+#' @importFrom grDevices col2rgb
 #' @name kableExtra-package
 #' @aliases kableExtra
 #' @docType package
diff --git a/R/spec_tools.R b/R/spec_tools.R
index bd27df4..f62f9e3 100644
--- a/R/spec_tools.R
+++ b/R/spec_tools.R
@@ -58,8 +58,8 @@
 #' @param begin Smallest degree to rotate. Default is 0
 #' @param end Largest degree to rotate. Default is 359.
 #' @export
-spec_angle <- function(x) {
-  x <- round(rescale(x, c(0, 359)))
+spec_angle <- function(x, begin, end) {
+  x <- round(rescale(x, c(begin, end)))
   x[is.na(x)] <- 0
   return(x)
 }