calculation functions that use the groups option now warn if groups is used without cols.

relates to #233

Author: zachary-foster

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: metacoder
 Title: Tools for Parsing, Manipulating, and Graphing Taxonomic Abundance Data
-Version: 0.3.1
+Version: 0.3.1.9001
 Authors@R: c(person("Zachary", "Foster", email =
         "zacharyfoster1989@gmail.com", role = c("aut", "cre")),
         person("Niklaus", "Grunwald", email =

NEWS.md

@@ -1,5 +1,9 @@
 # News 
 
+## Development version
+
+* calculation functions that use the `groups` option now warn if `groups` is used without `cols`.
+
 ##  metacoder 0.3.1
 
 ### Bug fixes

R/calculations--internal.R

@@ -83,6 +83,12 @@ get_numeric_cols <- function(obj, data, cols = NULL) {
 #' @keywords internal
 do_calc_on_num_cols <- function(obj, data, func, cols = NULL, groups = NULL,
                                 other_cols = FALSE, out_names = NULL) {
+  
+  # Warn if groups is used with no cols specified
+  if (is.null(cols) && !is.null(groups)) {
+    message('NOTE: Using the "groups" option without the "cols" option can yeild incorrect results if the column order is different from the group order.\n')
+  }
+  
   # Get input table
   input <- get_taxmap_table(obj, data)