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