On 06/04/2008, Anne Archibald [EMAIL PROTECTED] wrote:
On 05/04/2008, Stéfan van der Walt [EMAIL PROTECTED] wrote:
Some discussion recently took place around raising a square matrices
to integer powers. See ticket #601:
http://scipy.org/scipy/numpy/ticket/601
Anne
Hi all,
I tried to use the new function matrix_power, but I can't
find it.
matrix_power(array([[0,1],[-1,0]]),10)
Traceback (most recent call last):
File stdin, line 1, in ?
NameError: name 'matrix_power' is not defined
numpy.__version__
'1.0.5.dev4968'
Am I missing something ?
Nils
OK, here's a patch for:
#718: Bug with numpy.float32.tolist
Can someone commit it (I hope someone has committed the other patches
i've sent)?
James
--- arrayobject.c.old 2008-04-06 13:08:37.0 +0100
+++ arrayobject.c 2008-04-06 13:10:57.0 +0100
@@ -1870,8 +1870,11 @@
if
James Philbin wrote:
OK, here's a patch for:
#718: Bug with numpy.float32.tolist
Can someone commit it (I hope someone has committed the other patches
i've sent)?
I don't think this patch should be committed without more discussion.
This changes behavior and it is intentional that
On Sun, 6 Apr 2008, James Philbin apparently wrote:
OK, here's a patch for:
#718: Bug with numpy.float32.tolist
My impression has always been that to ensure
a patch gets appropriate consideration it
should be attached to a ticket...
fwiw,
Alan Isaac
On Sun, 6 Apr 2008, Stéfan van der Walt apparently wrote:
I'd be glad if you would review the changeset and comment.
Just checking:
it's important to me that this won't change
the behavior of boolean matrices, but I don't
see a test for this. E.g., ::
import numpy as N
A = N.mat('1
On 06/04/2008, Alan G Isaac [EMAIL PROTECTED] wrote:
Just checking:
it's important to me that this won't change
the behavior of boolean matrices, but I don't
see a test for this. E.g., ::
import numpy as N
A = N.mat('1 0;1 1',dtype='bool')
A**2
matrix([[ True,
On 06/04/2008, Alan G Isaac [EMAIL PROTECTED] wrote:
Just checking:
it's important to me that this won't change
the behavior of boolean matrices, but I don't
see a test for this. E.g., ::
import numpy as N
A = N.mat('1 0;1 1',dtype='bool')
A**2
matrix([[ True,
On Sun, Apr 6, 2008 at 12:59 PM, Alan G Isaac [EMAIL PROTECTED] wrote:
On 06/04/2008, Alan G Isaac [EMAIL PROTECTED] wrote:
Just checking:
it's important to me that this won't change
the behavior of boolean matrices, but I don't
see a test for this. E.g., ::
import numpy as
On 06/04/2008, Alan G Isaac [EMAIL PROTECTED] wrote:
On Sun, 6 Apr 2008, James Philbin apparently wrote:
OK, here's a patch for:
#718: Bug with numpy.float32.tolist
My impression has always been that to ensure
a patch gets appropriate consideration it
should be attached to a
On Sun, 6 Apr 2008, Charles R Harris wrote:
The boolean algebra is a field and the correct addition is xor, which is
the same as addition modulo 2. This makes all matrices with determinant 1
invertible. This isn't the current convention, however, as it was when
Caratheodory was writing on
On Sun, Apr 6, 2008 at 2:34 PM, Alan G Isaac [EMAIL PROTECTED] wrote:
On Sun, 6 Apr 2008, Charles R Harris wrote:
The boolean algebra is a field and the correct addition is xor, which
is
the same as addition modulo 2. This makes all matrices with determinant
1
invertible. This isn't the
Note this message has been posted to numpy-discussion and python-dev.
Sorry for the multiple posting but I thought both python devs and
numpy users will be interested. If you believe your list should not
receive this email, let me know. Also I just wanted to introduce
myself since I may ask
and for negative powers some sort of floating-point
inverse.
That deserves discussion.
Not all invertible boolean matrices have an inverse in the algebra.
Just the orthogonal ones do.
I guess I would special case inverses for Boolean matrices.
Just test if the matrix B is
On Apr 5, 2008, at 2:01 PM, Bruce Southey wrote:
Hi,
I have been investigating Ticket #605 'Incorrect behavior of
numpy.histogram' (http://scipy.org/scipy/numpy/ticket/605 ).
I think that my preference depends on the definition of what
the bin number means. If the bin numbers are the lower
On Sun, 6 Apr 2008, Anne Archibald apparently wrote:
I am not aware of any algorithm for finding inverses, or
even determining which matrices are invertible, in the
peculiar Boolean arithmetic we use.
Again, it is *not* peculiar, it is very standard for
boolean matrices. And with this
On Sun, 6 Apr 2008, Charles R Harris apparently wrote:
I prefer the modern usage myself as it is closer to the
accepted logic operations, but applying algebraic
manipulations like powers and matrix inverses in that
context leads to strange results.
I have not really thought much about
Hi,
I was just going through tidying up the documentation for all the many
functions in numpy that compute standard deviations or variances (the
functions, the methods, the methods on matrices, the methods on
maskedarrays, all needed their docstrings updated in approximately the
same way). I
On Sun, Apr 6, 2008 at 8:51 PM, Alan G Isaac [EMAIL PROTECTED] wrote:
On Sun, 6 Apr 2008, Charles R Harris apparently wrote:
I prefer the modern usage myself as it is closer to the
accepted logic operations, but applying algebraic
manipulations like powers and matrix inverses in that
Rahul Garg wrote:
Note this message has been posted to numpy-discussion and python-dev.
Sorry for the multiple posting but I thought both python devs and
numpy users will be interested. If you believe your list should not
receive this email, let me know. Also I just wanted to introduce
What will be the licensing of this project? Do you know yet?
I have a couple of comments because I've been thinking along these lines.
What is Spyke?
In many performance critical projects, it is often necessary to
rewrite parts of the application in C. However writing C wrappers can
be time
Anne Archibald wrote:
Hi,
I was just going through tidying up the documentation for all the many
functions in numpy that compute standard deviations or variances (the
functions, the methods, the methods on matrices, the methods on
maskedarrays, all needed their docstrings updated in
On Sun, 6 Apr 2008, Charles R Harris apparently wrote:
You mean as edges in a directed graph?
Yes.
Naturally a boolean matrix is not the most compact
representation of a directed graph, especially a
sparse one. However it can be convenient.
If B is a boolean matrix such that Bij=1 if there
On Sun, Apr 6, 2008 at 10:38 PM, Alan G Isaac [EMAIL PROTECTED] wrote:
On Sun, 6 Apr 2008, Charles R Harris apparently wrote:
You mean as edges in a directed graph?
Yes.
Naturally a boolean matrix is not the most compact
representation of a directed graph, especially a
sparse one.
24 matches
Mail list logo
