Hi python gurus, I have some questions when I'm using python numeric:
1. When I do v = u[:, :], it seems u and v still point to the same memory. e.g. When I do v[1,1]=0, u[1,1] will be zero out as well. What's the right way to duplicate an array? Now I have to do v = dot(u, identity(N)), which is kind of silly.
Hmm... I don't know Numeric, but in numarray (Numeric's replacement), you just call the copy method:
py> u = na.arange(6, shape=(2, 3))
py> v = u.copy()
py> v[0,0] = 100
py> u
array([[0, 1, 2],
[3, 4, 5]])
py> v
array([[100, 1, 2],
[ 3, 4, 5]])2. Is there a way to do Matlab style slicing? e.g. if I have i = array([0, 2]) x = array([1.1, 2.2, 3.3, 4.4]) I wish y = x(i) would give me [1.1, 3.3]
This also works exactly as you'd hope in numarray.
py> i = na.array([0, 2]) py> x = na.array([1.1, 2.2, 3.3, 4.4]) py> x[i] array([ 1.1, 3.3])
Do you have any reason that you have to use Numeric? Or can you upgrade to numarray?
Steve -- http://mail.python.org/mailman/listinfo/python-list
