Squashed 'subtree/rabit/' changes from 4ebe657..fb13cab

fb13cab change makefile
1479e37 fixed small bug in mpi submission script
0ca7a63 Update README.md
5ef4830 ok
93a1338 chg note

git-subtree-dir: subtree/rabit
git-subtree-split: fb13cab216b795f86dc90547b71c0f730766affa

Makefile

@@ -1,5 +1,6 @@
-export CC  = gcc
+ifndef 
 export CXX = g++
+endif
 export MPICXX = mpicxx
 export LDFLAGS= -Llib
 export WARNFLAGS= -Wall -Wextra -Wno-unused-parameter -Wno-unknown-pragmas -pedantic 

README.md

@@ -5,6 +5,7 @@ rabit is a light weight library that provides a fault tolerant interface of Allr
 * [Tutorial](guide)
 * [API Documentation](http://homes.cs.washington.edu/~tqchen/rabit/doc)
 * You can also directly read the [interface header](include/rabit.h)
+* [Machine Learning Tools](rabit-learn)
 
 Features
 ====
@@ -26,3 +27,11 @@ Use Rabit
 * Add lib to the library path and include to the include path of compiler
 * Languages: You can use rabit in C++ and python
   - It is also possible to port the library to other languages
+
+Contributing
+====
+Rabit is an open-source library, contributions are welcomed, including:
+* The rabit core library.
+* Customized tracker script for new platforms and interface of new languages.
+* Toolkits, benchmarks, resource (links to related repos).
+* Tutorial and examples about the library.

rabit-learn/README.md

@@ -8,7 +8,7 @@ It also contain links to the Machine Learning packages that uses rabit.
 Toolkits
 ====
 * [KMeans Clustering](kmeans)
-* [XGBoost: eXtreme Gradient Boosting](https://github.com/tqchen/xgboost/tree/unity/multi-node)
+* [XGBoost: eXtreme Gradient Boosting](https://github.com/tqchen/xgboost/tree/master/multi-node)
   - xgboost is a very fast boosted tree(also known as GBDT) library, that can run more than
     10 times faster than existing packages
   - Rabit carries xgboost to distributed enviroment, inheritating all the benefits of xgboost

tracker/rabit_mpi.py

@@ -35,7 +35,7 @@ def mpi_submit(nslave, worker_args):
     if args.hostfile is None:
         cmd = ' '.join(['mpirun -n %d' % (nslave)] + args.command + worker_args) 
     else:
-        ' '.join(['mpirun -n %d --hostfile %s' % (nslave, args.hostfile)] + args.command + worker_args)
+        cmd = ' '.join(['mpirun -n %d --hostfile %s' % (nslave, args.hostfile)] + args.command + worker_args)
     print cmd
     subprocess.check_call(cmd, shell = True)