complete refactor data.h, now replies on iterator to access column

Makefile

@@ -10,23 +10,22 @@ else
 	export CFLAGS = -Wall -O3 -msse2 -Wno-unknown-pragmas -fopenmp  -funroll-loops 
 endif
 
-# expose these flags to R CMD SHLIB
-export PKG_CPPFLAGS = $(CFLAGS) -DXGBOOST_CUSTOMIZE_ERROR_
-
 # specify tensor path
-BIN = xgboost
-OBJ = 
-SLIB = wrapper/libxgboostwrapper.so 
-RLIB = wrapper/libxgboostR.so 
+BIN =
+OBJ = updater.o gbm.o xgboost_main.o
+#SLIB = wrapper/libxgboostwrapper.so 
+#RLIB = wrapper/libxgboostR.so 
 .PHONY: clean all R python
 
-all: $(BIN) wrapper/libxgboostwrapper.so
-R: wrapper/libxgboostR.so
-python: wrapper/libxgboostwrapper.so
-xgboost: src/xgboost_main.cpp src/io/io.cpp src/data.h src/tree/*.h src/tree/*.hpp src/gbm/*.h src/gbm/*.hpp src/utils/*.h src/learner/*.h src/learner/*.hpp 
+all: $(BIN) $(OBJ)
+#python: wrapper/libxgboostwrapper.so
+#xgboost: src/xgboost_main.cpp src/io/io.cpp src/data.h src/tree/*.h src/tree/*.hpp src/gbm/*.h src/gbm/*.hpp src/utils/*.h src/learner/*.h src/learner/*.hpp 
+
 # now the wrapper takes in two files. io and wrapper part
-wrapper/libxgboostwrapper.so: wrapper/xgboost_wrapper.cpp src/io/io.cpp src/*.h src/*/*.hpp src/*/*.h
-wrapper/libxgboostR.so: wrapper/xgboost_wrapper.cpp wrapper/xgboost_R.cpp src/io/io.cpp src/*.h src/*/*.hpp src/*/*.h
+#wrapper/libxgboostwrapper.so: wrapper/xgboost_wrapper.cpp src/io/io.cpp src/*.h src/*/*.hpp src/*/*.h
+updater.o: src/tree/updater.cpp 
+gbm.o: src/gbm/gbm.cpp 
+xgboost_main.o: src/xgboost_main.cpp
 
 $(BIN) : 
 	$(CXX) $(CFLAGS) $(LDFLAGS) -o $@ $(filter %.cpp %.o %.c, $^)
@@ -34,9 +33,6 @@ $(BIN) :
 $(SLIB) :
 	$(CXX) $(CFLAGS) -fPIC $(LDFLAGS) -shared -o $@ $(filter %.cpp %.o %.c, $^)
 
-$(RLIB) :
-	R CMD SHLIB -c -o $@ $(filter %.cpp %.o %.c, $^)
-
 $(OBJ) : 
 	$(CXX) -c $(CFLAGS) -o $@ $(firstword $(filter %.cpp %.c, $^) )