2011-12-27 231 views
4

我想要做SVD上的稀疏矩阵通过使用SciPy的:稀疏矩阵:ValueError异常:基质类型必须是 'F', 'd', 'F',或 'd'

from svd import compute_svd 
print("The size of raw matrix: "+str(len(raw_matrix))+" * "+str(len(raw_matrix[0]))) 

from scipy.sparse import dok_matrix 
dok = dok_matrix(raw_matrix) 

matrix = compute_svd(dok) 

功能compute_svd是我的自定义模块,像这样:

def compute_svd(matrix): 
    from scipy.sparse import linalg 
    from scipy import dot, mat 
    # e.g., matrix = [[2,1,0,0], [4,3,0,0]] 
# matrix = mat(matrix); 
# print "Original matrix:" 
# print matrix 
    U, s, V = linalg.svds(matrix) 
    print "U:" 
    print U 
    print "sigma:" 
    print s 
    print "VT:" 
    print V 
    dimensions = 1 
    rows,cols = matrix.shape 
    #Dimension reduction, build SIGMA' 
    for index in xrange(dimensions, rows): 
     s[index]=0 
    print "reduced sigma:" 
    print s 
    #Reconstruct MATRIX' 
# from scipy import dot 
    reconstructedMatrix= dot(dot(U,linalg.diagsvd(s,len(matrix),len(V))),V) 
    #Print transform 
    print "reconstructed:" 
    print reconstructedMatrix 

    return reconstructedMatrix 

我得到一个异常:

Traceback (most recent call last): 
    File "D:\workspace\PyQuEST\src\Practice\baseline_lsi.py", line 96, in <module> 
    matrix = compute_svd(dok) 
    File "D:\workspace\PyQuEST\src\Practice\svd.py", line 13, in compute_svd 
    U, s, V = linalg.svds(matrix) 
    File "D:\Program\Python26\lib\site-packages\scipy\sparse\linalg\eigen\arpack\arpack.py", line 1596, in svds 
    eigvals, eigvec = eigensolver(XH_X, k=k, tol=tol ** 2) 
    File "D:\Program\Python26\lib\site-packages\scipy\sparse\linalg\eigen\arpack\arpack.py", line 1541, in eigsh 
    ncv, v0, maxiter, which, tol) 
    File "D:\Program\Python26\lib\site-packages\scipy\sparse\linalg\eigen\arpack\arpack.py", line 519, in __init__ 
    ncv, v0, maxiter, which, tol) 
    File "D:\Program\Python26\lib\site-packages\scipy\sparse\linalg\eigen\arpack\arpack.py", line 326, in __init__ 
    raise ValueError("matrix type must be 'f', 'd', 'F', or 'D'") 
ValueError: matrix type must be 'f', 'd', 'F', or 'D' 

这是我第一次这样做。我应该如何解决它?有任何想法吗?谢谢!

回答

4

你必须使用float或double。你似乎正在使用不受支持的矩阵类型的DOK?

稀疏SVD:http://docs.scipy.org/doc/scipy/reference/generated/scipy.sparse.linalg.svds.html

+0

我想我的问题是compute_svd模块中。我以前使用过普通矩阵。但我不知道如何转换为稀疏矩阵。 – Munichong 2011-12-27 22:49:37

+0

取出稀疏矩阵并将其复制到完整矩阵。 afaik没有稀疏的svd模块。 – Anycorn 2011-12-27 22:51:36

+0

它有scipy.sparse.linalg.svds。 http://docs.scipy.org/doc/scipy/reference/sparse.linalg.html – Munichong 2011-12-27 22:59:21

6

添加到Anycorn的回答,是的,你需要上溯造型你的矩阵浮动或双。这可以用函数来完成: asfptype()从scipy.sparse.coo_matrix

添加此行上溯造型就打电话linalg.svds前:

matrix.asfptype() 
U, s, V = linalg.svds(matrix)