Source Code for Module parsimony.utils.check_arrays'

 1  # -*- coding: utf-8 -*- 
 2  """ 
 3  Created on Mon Jul 29 17:37:17 2013 
 4   
 5  Copyright (c) 2013-2014, CEA/DSV/I2BM/Neurospin. All rights reserved. 
 6   
 7  @author:  Edouard Duchesnay 
 8  @email:   edouard.duchesnay@cea.fr 
 9  @license: BSD 3-clause. 
10  """ 
11  import numpy as np 
12   
13   
14 -def check_arrays(*arrays): 
15      """Checks that: 
16          - Lists are converted to numpy arrays. 
17          - All arrays are cast to float. 
18          - All arrays have consistent first dimensions. 
19          - Arrays are at least 2D arrays, if not they are reshaped. 
20   
21      Parameters 
22      ---------- 
23      *arrays: Sequence of arrays or scipy.sparse matrices with same shape[0] 
24              Python lists or tuples occurring in arrays are converted to 2D 
25              numpy arrays. 
26   
27      Examples 
28      -------- 
29      >>> import numpy as np 
30      >>> check_arrays([1, 2], np.array([3, 4]), np.array([[1., 2.], [3., 4.]])) 
31      [array([[ 1.], 
32             [ 2.]]), array([[ 3.], 
33             [ 4.]]), array([[ 1.,  2.], 
34             [ 3.,  4.]])] 
35      """ 
36      if len(arrays) == 0: 
37          return None 
38   
39      n_samples = None 
40      checked_arrays = [] 
41      for array in arrays: 
42          # Recast input as float array 
43          array = np.asarray(array, dtype=np.float) 
44   
45          if n_samples is None: 
46              n_samples = array.shape[0] 
47          if array.shape[0] != n_samples: 
48              raise ValueError("Found array with dim %d. Expected %d" 
49                               % (array.shape[0], n_samples)) 
50          if len(array.shape) == 1: 
51              array = array[:, np.newaxis] 
52   
53          checked_arrays.append(array) 
54   
55      return checked_arrays[0] if len(checked_arrays) == 1 else checked_arrays 
56   
57   
58  if __name__ == "__main__": 
59      import doctest 
60      doctest.testmod() 
61