added roxygen & fixed ggbiplot() library() calls

DESCRIPTION

@@ -9,9 +9,13 @@ Description: A ggplot2 based biplot.  It provides a drop-in
     replacement for biplot.princomp(). It implements a
     biplot and scree plot using ggplot2.
 Depends:
-    ggplot2, plyr, scales, grid
+    ggplot2,
+    plyr,
+    scales,
+    grid
 License: GPL-2
 URL: http://github.com/vqv/ggbiplot
 Collate:
     'ggbiplot.r'
     'ggscreeplot.r'
+RoxygenNote: 7.1.1

NAMESPACE

@@ -1,2 +1,8 @@
+# Generated by roxygen2: do not edit by hand
+
 export(ggbiplot)
 export(ggscreeplot)
+import(ggplot2)
+import(grid)
+import(plyr)
+import(scales)

R/ggbiplot.r

@@ -37,6 +37,14 @@
 #' @param varname.size    size of the text for variable names
 #' @param varname.adjust  adjustment factor the placement of the variable names, >= 1 means farther from the arrow
 #' @param varname.abbrev  whether or not to abbreviate the variable names
+#' @param circle.prob     (in progress)
+#' @param ...             (in progress)
+#'
+#'
+#' @import ggplot2
+#' @import plyr
+#' @import scales
+#' @import grid
 #'
 #' @return                a ggplot2 plot
 #' @export
@@ -54,11 +62,6 @@ ggbiplot <- function(pcobj, choices = 1:2, scale = 1, pc.biplot = TRUE,
                       varname.size = 3, varname.adjust = 1.5, 
                       varname.abbrev = FALSE, ...)
 {
-  library(ggplot2)
-  library(plyr)
-  library(scales)
-  library(grid)
-
   stopifnot(length(choices) == 2)
 
   # Recover the SVD

ggbiplot.Rproj

@@ -15,3 +15,4 @@ LaTeX: XeLaTeX
 BuildType: Package
 PackageUseDevtools: Yes
 PackageInstallArgs: --no-multiarch --with-keep.source
+PackageRoxygenize: rd,collate,namespace,vignette