[Numpy-discussion] help(numpy.dot) Hmmm.
Charles R Harris
charlesr.harris@gmail....
Sun Dec 20 20:52:18 CST 2009
On Sun, Dec 20, 2009 at 7:37 PM, Wayne Watson
<sierra_mtnview@sbcglobal.net>wrote:
> I've just become acquainted with the help command in WinXP IDLE.
> help(numyp.sin) works fine. What's going on with dot?
>
> >>> help(numpy.core.multiarray.dot)
> Help on built-in function dot in module numpy.core.multiarray:
>
> dot(...)
>
> Is there help for dot?
>
>
Yes, but you may be using an old version of numpy. What does
numpy.__version__ say? You can also find documentation on the
scipy.orgsite. Here is part of the current help:
Help on built-in function dot in module numpy.core._dotblas:
dot(...)
dot(a, b)
Dot product of two arrays.
For 2-D arrays it is equivalent to matrix multiplication, and for 1-D
arrays to inner product of vectors (without complex conjugation). For
N dimensions it is a sum product over the last axis of `a` and
the second-to-last of `b`::
dot(a, b)[i,j,k,m] = sum(a[i,j,:] * b[k,:,m])
Parameters
----------
a : array_like
First argument.
b : array_like
Second argument.
Returns
-------
output : ndarray
Returns the dot product of `a` and `b`. If `a` and `b` are both
scalars or both 1-D arrays then a scalar is returned; otherwise
an array is returned.
Raises
------
ValueError
If the last dimension of `a` is not the same size as
the second-to-last dimension of `b`.
See Also
--------
vdot : Complex-conjugating dot product.
tensordot : Sum products over arbitrary axes.
Examples
--------
...
Chuck
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.scipy.org/pipermail/numpy-discussion/attachments/20091220/ca8cfd38/attachment.html
More information about the NumPy-Discussion
mailing list