Added help notes on ngrams and skips to indicate how to use them for a single namespace.

1 files changed, 2 insertions, 2 deletions

diff --git a/vowpalwabbit/parse_args.cc b/vowpalwabbit/parse_args.cc
index 5519c091..b6afabae 100644
--- a/vowpalwabbit/parse_args.cc
+++ b/vowpalwabbit/parse_args.cc
@@ -205,8 +205,8 @@ vw* parse_args(int argc, char *argv[])
     ("noconstant", "Don't add a constant feature")
     ("constant,C", po::value<float>(&(all->initial_constant)), "Set initial value of constant")
     ("sort_features", "turn this on to disregard order in which features have been defined. This will lead to smaller cache sizes")
-    ("ngram", po::value< vector<string> >(), "Generate N grams")
-    ("skips", po::value< vector<string> >(), "Generate skips in N grams. This in conjunction with the ngram tag can be used to generate generalized n-skip-k-gram.")
+    ("ngram", po::value< vector<string> >(), "Generate N grams. To generate N grams for a single namespace 'foo', arg should be fN.")
+    ("skips", po::value< vector<string> >(), "Generate skips in N grams. This in conjunction with the ngram tag can be used to generate generalized n-skip-k-gram. To generate n-skips for a single namespace 'foo', arg should be fn.")
     ("affix", po::value<string>(), "generate prefixes/suffixes of features; argument '+2a,-3b,+1' means generate 2-char prefixes for namespace a, 3-char suffixes for b and 1 char prefixes for default namespace")
     ("spelling", po::value< vector<string> >(), "compute spelling features for a give namespace (use '_' for default namespace)");
     ;