def read_double_matrix(fid, rows, cols):
 return _unpack_matrix(fid, rows, cols, dtype='>f8', out_dtype=np.float64)

def read_double_matrix ( fid , rows , cols ) : return _unpack_matrix ( fid , rows , cols , dtype = '>f8' , out_dtype = np . float64 )
read 64bit float matrix from bti file .