Update version (#198)

* Update docstring

* Update version

Author: AshlinHarris

Project.toml

@@ -1,7 +1,7 @@
 name = "PreprocessMD"
 uuid = "f785c8c6-3d80-4813-989a-2eb5f27d6bef"
 authors = ["Ashlin Harris <ashlin_harris@brown.edu>"]
-version = "3.1.0"
+version = "3.1.1"
 
 [deps]
 DataFrames = "a93c6f00-e57d-5684-b7b6-d8193f3e46c0"

src/PreprocessMD.jl

@@ -35,7 +35,10 @@ const OPTIONAL_INT_TYPES = Union{Int,Nothing}
 """
 	function add_label_column!(feature_df, source_df, new_column[, id])
 
-Add column to a DataFrame based on symbol presence in the target DataFrame
+Add a label column to a DataFrame based on symbol presence in the target DataFrame
+
+A column from the target is not copied.
+Instead, the new column is a `CategoricalArray` containing `true` for any ID that is present in the target and `false` otherwise.
 
 # Arguments
 - `feature_df::AbstractDataFrame`: feature DataFrame to which label column is added