add row map example

multi-node/row-split/machine-row-map.sh

@@ -0,0 +1,20 @@
+#!/bin/bash
+if [[ $# -ne 1 ]]
+then
+    echo "Usage: nprocess"
+    exit -1
+fi
+
+rm -rf train-machine.row* *.model
+k=$1
+# make machine data
+cd ../../demo/regression/
+python mapfeat.py
+python mknfold.py machine.txt 1
+cd -
+
+# split the lib svm file into k subfiles
+python splitrows.py ../../demo/regression/machine.txt.train train-machine $k
+
+# run xgboost mpi, take data from stdin
+../submit_job_tcp.py $k "bash map.sh train-machine.row ../../xgboost machine-row.conf dsplit=row num_round=3 data=stdin"

multi-node/row-split/map.sh

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+# a simple script to simulate mapreduce mapper
+echo "cat $1$OMPI_COMM_WORLD_RANK | ${@:2}"
+cat $1$OMPI_COMM_WORLD_RANK | ${@:2}