diff options
Diffstat (limited to 'scipy/base/twodim_base.py')
| -rw-r--r-- | scipy/base/twodim_base.py | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/scipy/base/twodim_base.py b/scipy/base/twodim_base.py index 1ac7b43e7..f8cc367c8 100644 --- a/scipy/base/twodim_base.py +++ b/scipy/base/twodim_base.py @@ -2,7 +2,8 @@ """ -__all__ = ['diag','eye','fliplr','flipud','rot90','tri','triu','tril'] +__all__ = ['diag','eye','fliplr','flipud','rot90','tri','triu','tril', + 'vander'] from numeric import * import sys @@ -40,19 +41,19 @@ def rot90(m, k=1): elif k == 2: return fliplr(flipud(m)) else: return fliplr(transpose(m)) # k==3 -def eye(N, M=None, k=0, typecode='d'): +def eye(N, M=None, k=0, dtype='d'): """ eye returns a N-by-M 2-d array where the k-th diagonal is all ones, and everything else is zeros. """ if M is None: M = N if type(M) == type('d'): - typecode = M + dtype = M M = N m = equal(subtract.outer(arange(N), arange(M)),-k) - if typecode is None: + if dtype is None: return m else: - return m.astype(typecode) + return m.astype(dtype) def diag(v, k=0): """ returns the k-th diagonal if v is a array or returns a array @@ -63,9 +64,9 @@ def diag(v, k=0): if len(s)==1: n = s[0]+abs(k) if k > 0: - v = concatenate((zeros(k, v.typecode()),v)) + v = concatenate((zeros(k, v.dtype),v)) elif k < 0: - v = concatenate((v,zeros(-k, v.typecode()))) + v = concatenate((v,zeros(-k, v.dtype))) return eye(n, k=k)*v elif len(s)==2: v = add.reduce(eye(s[0], s[1], k=k)*v) @@ -110,4 +111,21 @@ def triu(m, k=0): +# from matplotlib +def vander(x, N=None): + """ + X = vander(x,N=None) + + The Vandermonde matrix of vector x. The i-th column of X is the + the i-th power of x. N is the maximum power to compute; if N is + None it defaults to len(x). + + """ + if N is None: N=len(x) + X = ones( (len(x),N), x.dtypechar) + for i in range(N-1): + X[:,i] = x**(N-i-1) + return X + + |