@@ -92,38 +92,47 @@ def _ssmatrix(data, axis=1):
9292
9393 Returns
9494 -------
95- arr : 2D array, with shape (0, 0) if a is empty
95+ arr : real or complex 2D array, with shape (0, 0) if a is empty
9696
9797 """
98- # Convert the data into an array or matrix, as configured
98+
9999 # If data is passed as a string, use (deprecated?) matrix constructor
100+ if isinstance (data , str ):
101+ arr = np .asarray (np .matrix (data ))
102+ else :
103+ # TODO: Is it okay to use a view here (asarray or copy=False)?
104+ arr = np .array (data )
105+
106+ # find out if we need to cast to float or complex
107+ arr_ndtype = np .result_type (np .float64 , arr )
108+
109+ # Get a view of the data as 2D array or matrix, as configured
100110 if config .defaults ['statesp.use_numpy_matrix' ]:
101- arr = np .matrix (data , dtype = float )
102- elif isinstance (data , str ):
103- arr = np .array (np .matrix (data , dtype = float ))
111+ arr = np .asmatrix (arr , dtype = arr_ndtype )
104112 else :
105- arr = np .array (data , dtype = float )
113+ arr = np .asarray (arr , dtype = arr_ndtype )
114+
106115 ndim = arr .ndim
107116 shape = arr .shape
108117
109118 # Change the shape of the array into a 2D array
110119 if (ndim > 2 ):
111120 raise ValueError ("state-space matrix must be 2-dimensional" )
112121
113- elif ( ndim == 2 and shape == (1 , 0 )) or \
114- ( ndim == 1 and shape == (0 , )) :
115- # Passed an empty matrix or empty vector; change shape to (0, 0)
122+ # note: default empty matrix is (1,0)
123+ if shape in [( 1 , 0 ), (0 , )] :
124+ # Passed an empty matrix, list or array vector; change shape to (0, 0)
116125 shape = (0 , 0 )
117126
118127 elif ndim == 1 :
119- # Passed a row or column vector
128+ # Passed a non-empty row or column vector
120129 shape = (1 , shape [0 ]) if axis == 1 else (shape [0 ], 1 )
121130
122131 elif ndim == 0 :
123132 # Passed a constant; turn into a matrix
124133 shape = (1 , 1 )
125134
126- # Create the actual object used to store the result
135+ # create the correct view of the data
127136 return arr .reshape (shape )
128137
129138
0 commit comments