good

python/xgboost.py

@@ -1,5 +1,7 @@
 # module for xgboost
 import ctypes 
+import numpy
+import scipy.sparse as scp
 
 # load in xgboost library
 xglib = ctypes.cdll.LoadLibrary('./libxgboostpy.so')
@@ -8,15 +10,57 @@ xglib = ctypes.cdll.LoadLibrary('./libxgboostpy.so')
 class REntry(ctypes.Structure):
     _fields_ = [("findex", ctypes.c_uint), ("fvalue", ctypes.c_float) ]
 
-
+# data matrix used in xgboost
 class DMatrix:
-    def __init__(self,fname = None):
-        self.__handle = xglib.XGDMatrixCreate();
-        if fname != None:
-            xglib.XGDMatrixLoad(self.__handle, ctypes.c_char_p(fname), 0)
+    # constructor
+    def __init__(self, data=None, label=None):
+        self.handle = xglib.XGDMatrixCreate();
+        if data == None:
+            return        
+        if type(data) is str:
+            xglib.XGDMatrixLoad(self.handle, ctypes.c_char_p(data), 1) 
+        elif type(data) is scp.csr_matrix:
+            self.__init_from_csr(data)
+        else:
+            try:
+                csr = scp.csr_matrix(data)
+                self.__init_from_csr(data)
+            except:
+                raise "DMatrix", "can not intialize DMatrix from"+type(data)                
+        if label != None:
+            self.set_label(label)
+
+    # convert data from csr matrix
+    def __init_from_csr(self,csr):
+        assert len(csr.indices) == len(csr.data)
+        xglib.XGDMatrixParseCSR( self.handle, 
+                                 ( ctypes.c_ulong  * len(csr.indptr) )(*csr.indptr),
+                                 ( ctypes.c_uint  * len(csr.indices) )(*csr.indices),
+                                 ( ctypes.c_float * len(csr.data) )(*csr.data),
+                                 len(csr.indptr), len(csr.data) )
+    # destructor
     def __del__(self):
-        xglib.XGDMatrixFree(self.__handle)
-
-dmata = DMatrix('xx.buffer')
-
+        xglib.XGDMatrixFree(self.handle)
+    # load data from file 
+    def load(self, fname):
+        xglib.XGDMatrixLoad(self.handle, ctypes.c_char_p(fname), 1)
+    # set label of dmatrix
+    def set_label(self, label):
+        xglib.XGDMatrixSetLabel(self.handle, (ctypes.c_float*len(label))(*label), len(label) );
+    # get label from dmatrix
+    def get_label(self):
+        GetLabel = xglib.XGDMatrixGetLabel
+        GetLabel.restype = ctypes.POINTER( ctypes.c_float )
+        length = ctypes.c_ulong()
+        labels = GetLabel(self.handle, ctypes.byref(length));
+        return [ labels[i] for i in xrange(length.value) ]
+    # append a row to DMatrix
+    def add_row(self, row):
+        xglib.XGDMatrixAddRow(self.handle, (REntry*len(row))(*row), len(row) );
+    
 
+mat = DMatrix('xx.buffer')
+lb = mat.get_label()
+print len(lb)
+mat.set_label(lb)
+mat.add_row( [(1,2), (3,4)] )