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2016-04-14 Thread Colin J. Williams
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Re: [Numpy-discussion] Advanced indexing: fancy vs. orthogonal

2015-04-02 Thread Colin J. Williams
On 02-Apr-15 4:35 PM, Eric Firing wrote: On 2015/04/02 10:22 AM, josef.p...@gmail.com wrote: Swapping the axis when slices are mixed with fancy indexing was a design mistake, IMO. But not fancy indexing itself. I'm not saying there should be no fancy indexing capability; I am saying that it

Re: [Numpy-discussion] Matrix Class

2015-02-12 Thread Colin J. Williams
Thanks Ryan. There are a number of good thoughts in your message. I'll try to keep track of them. Another respondent reported different results than mine. I'm in the process of re-installing to check. Colin W. On 11 February 2015 at 16:18, Ryan Nelson rnelsonc...@gmail.com wrote: Colin,

Re: [Numpy-discussion] Characteristic of a Matrix.

2015-02-04 Thread Colin J. Williams
On 06/01/2015 8:38 PM, Alexander Belopolsky wrote: On Tue, Jan 6, 2015 at 8:20 PM, Nathaniel Smith n...@pobox.com mailto:n...@pobox.com wrote: Since matrices are now part of some high school curricula, I urge that they be treated appropriately in Numpy. Further, I suggest that

Re: [Numpy-discussion] Characteristic of a Matrix.

2015-02-04 Thread Colin J. Williams
On 08/01/2015 1:19 PM, Ryan Nelson wrote: Colin, I'll second the endorsement of Sage; however, for teaching purposes, I would suggest Sage Math Cloud. It is a free, web-based version of Sage, and it does not require you or the students to install any software (besides a new-ish web

[Numpy-discussion] Characteristic of a Matrix.

2015-01-05 Thread Colin J. Williams
One of the essential characteristics of a matrix is that it be rectangular. This is neither spelt out or checked currently. The Doc description refers to a class: - *class *numpy.matrix[source] http://github.com/numpy/numpy/blob/v1.9.1/numpy/matrixlib/defmatrix.py#L206 Returns a matrix

[Numpy-discussion] Compiling Numpy-1.8.1

2014-07-29 Thread Colin J. Williams
This version of Numpy does not appear to be available as an installable binary. In any event, the LAPACK and other packages do not seem to be available with the installable versions. I understand that Windows Studio 2008 is normally used for Windows compiling. Unfortunately, this is no

Re: [Numpy-discussion] Compiling Numpy-1.8.1

2014-07-29 Thread Colin J. Williams
Oliver, Thanks. I've installed Windows Studio 2008 Express. I'll read your building on Winods Document. Colin W. On 29 July 2014 08:50, Olivier Grisel olivier.gri...@ensta.org wrote: 2014-07-29 14:24 GMT+02:00 Colin J. Williams c...@ncf.ca: This version of Numpy does not appear

Re: [Numpy-discussion] NumPy-Discussion Digest, Vol 90, Issue 83

2014-03-25 Thread Colin J. Williams
On 25-Mar-2014 1:00 PM, numpy-discussion-requ...@scipy.org wrote: Message: 3 Date: Mon, 24 Mar 2014 17:58:57 -0600 From: Charles R Harris charlesr.har...@gmail.com Subject: Re: [Numpy-discussion] Resolving the associativity/precedence debate for @ To: Discussion of Numerical Python

Re: [Numpy-discussion] NumPy-Discussion Digest, Vol 90, Issue 56

2014-03-17 Thread Colin J. Williams
Julian, I can see the need to recognize both column and row vectors, but why not with np.matrix? I can see no need for a new operator and hope to be able to comment more fully on PEP 465 in a few days. Colin W. On 17-Mar-2014 7:19 PM, numpy-discussion-requ...@scipy.org wrote: Send

Re: [Numpy-discussion] NumPy-Discussion Digest, Vol 90, Issue 45

2014-03-16 Thread Colin J. Williams
I would like to see the case made for @. Yes, I know that Guido has accepted the idea, but he has changed his mind before. The PEP seems neutral to retaining both np.matrix and @. Nearly ten years ago, Tim Peters http://legacy.python.org/dev/peps/pep-0020/ gave us: /There should be

[Numpy-discussion] Matrix peculiarities

2013-08-29 Thread Colin J. Williams
Ralf, Could you please elaborate on the matrix weaknesses? Is there any work planned to eliminate the peculiarities? Regards, Colin W. Subject: Re: [Numpy-discussion] Relative speed To: Discussion of Numerical

[Numpy-discussion] Python PEP 450

2013-08-16 Thread Colin J. Williams
This is to respond to Alan's message: Message: 7 Date: Fri, 16 Aug 2013 11:20:32 -0400 From: Alan G Isaac alan.is...@gmail.com Subject: [Numpy-discussion] PEP 450 (stats module for standard     library) To: Discussion of Numerical Python

[Numpy-discussion] Treatment of the Matrix by Numpy

2013-07-24 Thread Colin J. Williams
To: Discussion of Numerical Python numpy-discussion@scipy.org Message-ID: CAN06oV9E2Xsf=tgbyqgxpnt4lhan6twtbuyi8gagt-vg2qa...@mail.gmail.com Content-Type: text/plain; charset=ISO-8859-1 On Wed, Jul 24, 2013 at 8:53 AM, St?fan van der Walt ste...@sun.ac.za wrote: On Wed,

Re: [Numpy-discussion] NumPy-Discussion Digest, Vol 82, Issue 34

2013-07-19 Thread Colin J. Williams
ence, attempting to be extremely concise in technical writing is a common cause of awkward grammar problems like this. I do it all the time :)  -Rob On Thu, Jul 18, 2013 at 9:18 AM, Colin J. Williams cjwilliam...@gmail.com wrote: Re

[Numpy-discussion] User Guide

2013-07-18 Thread Colin J. Williams
Returning to numpy after a while away, I'm impressed with the style and content of the User Guide and the Reference.  This is to offer a Guide correction - I couldn't figure out how to offer the correction on-line. What is Numpy?

Re: [Numpy-discussion] Time Zones and datetime64

2013-04-12 Thread Colin J. Williams
On 12/04/2013 3:57 PM, Chris Barker - NOAA Federal wrote: On Fri, Apr 12, 2013 at 9:52 AM, Riccardo De Maria riccardodema...@gmail.com wrote: Not related to leap seconds and physically accurate time deltas, I have just noticed that SQLite has a nice

Re: [Numpy-discussion] Please stop bottom posting!!

2013-04-11 Thread Colin J. Williams
On 11/04/2013 7:20 PM, Paul Hobson wrote: On Wed, Apr 3, 2013 at 4:28 PM, Doug Coleman doug.cole...@gmail.com wrote: Also, gmail "bottom-posts" by default.

Re: [Numpy-discussion] Time Zones and datetime64

2013-04-10 Thread Colin J. Williams
On 09/04/2013 5:46 PM, Mark Wiebe wrote: On Mon, Apr 8, 2013 at 12:24 PM, Chris Barker - NOAA Federal chris.bar...@noaa.gov wrote: Recent discussion has made it clear that the timezone handling in

Re: [Numpy-discussion] ANN: NumPy 1.7.1rc1 release

2013-04-07 Thread Colin J. Williams
On 07/04/2013 1:03 AM, Ondřej Čertík wrote: On Tue, Mar 26, 2013 at 6:32 PM, Ondřej Čertík ondrej.cer...@gmail.com wrote: [...] Yes. I created an issue here for them to test it: https://github.com/scikit-learn/scikit-learn/issues/1809 Just to make

Re: [Numpy-discussion] Sources more confusing in Python

2013-04-07 Thread Colin J. Williams
On 07/04/2013 10:32 AM, Happyman wrote: Hello, I started using python 4-5 months ago. At that time I didn't realize there are incredibly many resource like modules, additional programs (ready one) in python. The problem is to which

Re: [Numpy-discussion] try to solve issue #2649 and revisit #473

2013-04-04 Thread Colin J. Williams
On 03/04/2013 7:11 PM, huangkan...@gmail.com wrote: Agree with the row-vector and column-vector thing. I notice that in ndarray multiplication, the 1-d array is treated as a column-vector. But in matrix multiplication, 1-d array is converted

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-23 Thread Colin J. Williams
On 23/03/2013 7:21 AM, Ralf Gommers wrote: On Fri, Mar 22, 2013 at 10:39 PM, Colin J. Williams cjwilliam...@gmail.com wrote: On 20/03/2013 11:12 AM, Frédéric Bastien

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-23 Thread Colin J. Williams
On 23/03/2013 12:05 AM, Chris Barker - NOAA Federal wrote: On Fri, Mar 22, 2013 at 2:39 PM, Colin J. Williams cjwilliam...@gmail.com wrote: I have updated to numpy 1.7.0 for each of the Pythons 2.7.3, 3.2.3 and 3.3.0

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-22 Thread Colin J. Williams
On 20/03/2013 11:12 AM, Frédéric Bastien wrote: On Wed, Mar 20, 2013 at 11:01 AM, Colin J. Williams cjwilliam...@gmail.com wrote: On 20/03/2013 10:30 AM, Frédéric Bastien wrote: Hi, win32 do not mean it is a 32 bits windows

[Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
I have a small program which builds random matrices for increasing matrix orders, inverts the matrix and checks the precision of the product.  At some point, one would expect operations to fail, when the memory capacity is exceeded.  In both Python 2.7

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
)) 2.41799631031e-05 1.13955868701e-05 3.64338191541e-05 1.13484781021e-05 1 loops, best of 3: 156 s per loop Intel i5, 4 GB of RAM and SSD. ATLAS installed from Fedora repository (I don't run heavy stuff on this computer). On 20 March 2013 14:46, Colin J. Williams c...@ncf.ca wrote: I have

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
. ATLAS installed from Fedora repository (I don't run heavy stuff on this computer). On 20 March 2013 14:46, Colin J. Williams c...@ncf.ca wrote: I have a small program which builds random matrices

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
. ATLAS installed from Fedora repository (I don't run heavy stuff on this computer). On 20 March 2013 14:46, Colin J. Williams c...@ncf.ca wrote: I have a small program which builds random matrices for increasing matrix orders, inverts the matrix and checks the precision of the product. At some

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
On 20/03/2013 11:06 AM, Jens Nielsen wrote: The python3 version is compiled without any optimised library and is falling back on a slow version. Where did you get this installation from? Jens From the

Re: [Numpy-discussion] Execution time difference between 2.7 and 3.2 using numpy

2013-03-20 Thread Colin J. Williams
On 20/03/2013 11:12 AM, Frédéric Bastien wrote: On Wed, Mar 20, 2013 at 11:01 AM, Colin J. Williams cjwilliam...@gmail.com wrote: On 20/03/2013 10:30 AM, Frédéric Bastien wrote: Hi, win32 do not mean it is a 32 bits windows

[Numpy-discussion] Synonym standards

2012-07-26 Thread Colin J. Williams
It seems that these standards have been adopted, which is good: The following import conventions are used throughout the NumPy source and documentation: import numpy as np import matplotlib as mpl import matplotlib.pyplot as plt Source:

Re: [Numpy-discussion] Synonym standards

2012-07-26 Thread Colin J. Williams
PM, Colin J. Williams fn...@ncf.ca wrote: It seems that these standards have been adopted, which is good: The following import conventions are used throughout the NumPy source and documentation: import numpy as np import matplotlib as mpl import matplotlib.pyplot as plt Source: https

Re: [Numpy-discussion] Synonym standards

2012-07-26 Thread Colin J. Williams
On 26/07/2012 4:57 PM, Benjamin Root wrote: On Thu, Jul 26, 2012 at 4:45 PM, Colin J. Williams fn...@ncf.ca wrote: It seems that these standards have been adopted, which is good

Re: [Numpy-discussion] Rounding to next lowest float

2011-10-11 Thread Colin J. Williams
If you are using integers, why not use Python's Long? Colin W. On 11/10/2011 2:00 PM, Matthew Brett wrote: Hi, Can anyone think of a clever way to round an integer to the next lowest integer represented in a particular floating point format? For example: In [247]: a = 2**25+3 This is out

Re: [Numpy-discussion] non-standard standard deviation

2009-12-06 Thread Colin J. Williams
On 04-Dec-09 10:54 AM, Bruce Southey wrote: On 12/04/2009 06:18 AM, yogesh karpate wrote: @ Pauli and @ Colin: Sorry for the late reply. I was busy in some other assignments. # As far as normalization by(n) is concerned then its common assumption that

Re: [Numpy-discussion] non-standard standard deviation

2009-12-05 Thread Colin J. Williams
On 04-Dec-09 05:21 AM, Pauli Virtanen wrote: pe, 2009-12-04 kello 11:19 +0100, Chris Colbert kirjoitti: Why cant the divisor constant just be made an optional kwarg that defaults to zero? It already is an optional kwarg that defaults to zero. Cheers, I suggested that 1

Re: [Numpy-discussion] non-standard standard deviation

2009-12-05 Thread Colin J. Williams
On 04-Dec-09 07:18 AM, yogesh karpate wrote: @ Pauli and @ Colin: Sorry for the late reply. I was busy in some other assignments. # As far as normalization by(n) is concerned then its common assumption that the population is normally distributed and

Re: [Numpy-discussion] non-standard standard deviation

2009-12-03 Thread Colin J. Williams
Yogesh, Could you explain the rationale for this choice please? Colin W. On 03-Dec-09 00:35 AM, yogesh karpate wrote: The thing is that the normalization by (n-1) is done for the no. of samples 20 or23(Not sure about this no. but sure about the thing that this no isnt greater than 25) and

Re: [Numpy-discussion] non-standard standard deviation

2009-11-29 Thread Colin J. Williams
On 29-Nov-09 17:13 PM, Dr. Phillip M. Feldman wrote: All of the statistical packages that I am currently using and have used in the past (Matlab, Minitab, R, S-plus) calculate standard deviation using the sqrt(1/(n-1)) normalization, which gives a result that is unbiased when sampling from a

[Numpy-discussion] Resize method

2009-11-23 Thread Colin J. Williams
Access by the interpreter prevents array resizing. Yes, one can use the function, in place of the method but this appears to require copying the whole array. If one sets b= a, then that reference can be deleted with del b. Is there any similar technique for the interpreter? Colin W. Python

Re: [Numpy-discussion] Resize method

2009-11-23 Thread Colin J. Williams
Christopher Barker wrote: Colin J. Williams wrote: Access by the interpreter prevents array resizing. yup -- resize is really fragile for that reason. It really should be used quite sparingly. Personally, I think it should probably only be used when wrapped with a higher level layer

Re: [Numpy-discussion] subclassing matrix

2008-01-12 Thread Colin J. Williams
Basilisk96 wrote: On Jan 12, 1:36 am, Timothy Hochberg [EMAIL PROTECTED] wrote: I believe that you need to look at __array_finalize__ and __array_priority__ (and there may be one other thing as well, I can't remember; it's late). Search for __array_finalize__ and that will probably help get

Re: [Numpy-discussion] subclassing matrix

2008-01-10 Thread Colin J. Williams
Basilisk96 wrote: Hello folks, In the course of a project that involved heavy use of geometry and linear algebra, I found it useful to create a Vector subclass of numpy.matrix (represented as a column vector in my case). Why not consider a matrix with a shape of (1, n) as a row vector and

Re: [Numpy-discussion] defmatrix.py

2007-03-27 Thread Colin J. Williams
Charles R Harris wrote: On 3/26/07, *Travis Oliphant* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: I think that might be the simplest thing, dot overrides subtypes. BTW, here is another ambiguity In [6]: dot(array([[1]]),ones(2))

Re: [Numpy-discussion] matrix indexing question

2007-03-27 Thread Colin J. Williams
Alan G Isaac wrote: On Mon, 26 Mar 2007, Colin J. Williams apparently wrote: One would expect the iteration over A to return row vectors, represented by (1, n) matrices. This is again simple assertion. **Why** would one expect this? Some people clearly do not. One person commented

Re: [Numpy-discussion] matrix indexing question

2007-03-26 Thread Colin J. Williams
Bill Baxter wrote: On 3/26/07, Colin J. Williams [EMAIL PROTECTED] wrote: Bill Baxter wrote: This may sound silly, but I really think seeing all those brackets is what makes it feel wrong. Matlab's output doesn't put it in your face that your 4 is really a matrix([[4]]), even though that's

Re: [Numpy-discussion] matrix indexing question

2007-03-26 Thread Colin J. Williams
Alan G Isaac wrote: On 3/26/07, Alan G Isaac [EMAIL PROTECTED] wrote: finds itself in basic conflict with the idea that I ought to be able to iterate over the objects in an iterable container. I mean really, does this not feel wrong? :: for item in x: print item.__repr__()

Re: [Numpy-discussion] matrix indexing question

2007-03-26 Thread Colin J. Williams
Alan G Isaac wrote: Alan G Isaac wrote: So this :: x[1] matrix([[1, 0]]) feels wrong. (Similarly when iterating across rows.) Of course I realize that I can just :: x.A[1] array([1, 0]) On Sun, 25 Mar 2007, Colin J. Williams apparently wrote: An array

Re: [Numpy-discussion] matrix indexing question

2007-03-26 Thread Colin J. Williams
Alan G Isaac wrote: On Mon, 26 Mar 2007, Colin J. Williams apparently wrote: Perhaps things would be clearer if we thought of the constituent groups of data in a matrix as being themselves matrices. This thinking of is what you have suggested before. You need to explain why

Re: [Numpy-discussion] Detect subclass of ndarray

2007-03-25 Thread Colin J. Williams
Alan G Isaac wrote: On Sat, 24 Mar 2007, Charles R Harris apparently wrote: Yes, that is what I am thinking. Given that there are only the two possibilities, row or column, choose the only one that is compatible with the multiplying matrix. The result will not always be a column vector, for

Re: [Numpy-discussion] Detect subclass of ndarray

2007-03-25 Thread Colin J. Williams
Colin J. Williams wrote: Alan G Isaac wrote: On Sat, 24 Mar 2007, Charles R Harris apparently wrote: Yes, that is what I am thinking. Given that there are only the two possibilities, row or column, choose the only one that is compatible with the multiplying matrix. The result

Re: [Numpy-discussion] Simple multi-arg wrapper for dot()

2007-03-25 Thread Colin J. Williams
Bill Baxter wrote: On 3/25/07, Robert Kern [EMAIL PROTECTED] wrote: Bill Baxter wrote: I don't know. Given our previous history with convenience functions with different calling semantics (anyone remember rand()?), I think it probably will confuse some people. I'd really like to see it

Re: [Numpy-discussion] matrix indexing question

2007-03-25 Thread Colin J. Williams
Alan G Isaac wrote: One thing keeps bugging me when I use numpy.matrix. All this is fine:: x=N.mat('1 1;1 0') x matrix([[1, 1], [1, 0]]) x[1,:] matrix([[1, 0]]) But it seems to me that I should be able to extract a matrix row as an array. This

Re: [Numpy-discussion] matrix indexing question

2007-03-25 Thread Colin J. Williams
Alan G Isaac wrote: Em Dom, 2007-03-25 Ã s 13:07 -0400, Alan G Isaac escreveu: x[1] matrix([[1, 0]]) feels wrong. (Similarly when iterating across rows.) On Sun, 25 Mar 2007, Paulo Jose da Silva e Silva apparently wrote: I think the point here is that if you are using matrices,

Re: [Numpy-discussion] matrix indexing question

2007-03-25 Thread Colin J. Williams
Bill Baxter wrote: On 3/26/07, Alan G Isaac [EMAIL PROTECTED] wrote: Em Dom, 2007-03-25 às 13:07 -0400, Alan G Isaac escreveu: x[1] matrix([[1, 0]]) feels wrong. (Similarly when iterating across rows.) On Sun, 25 Mar 2007, Paulo Jose da Silva e Silva apparently wrote: I think the

Re: [Numpy-discussion] Detect subclass of ndarray

2007-03-24 Thread Colin J. Williams
Charles R Harris wrote: On 3/24/07, *Alan G Isaac* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: On Fri, 23 Mar 2007, Charles R Harris apparently wrote: the following gives the wrong result: In [15]: I = matrix(eye(2)) In [16]: I*ones(2) Out[16]:

Re: [Numpy-discussion] Latest Array-Interface PEP

2007-01-04 Thread Colin J. Williams
Travis Oliphant wrote: I'm attaching my latest extended buffer-protocol PEP that is trying to get the array interface into Python. Basically, it is a translation of the numpy header files into something as simple as possible that can still be used to describe a complicated block of

Re: [Numpy-discussion] sum of two arrays with different shape?

2006-12-20 Thread Colin J. Williams
zhang yunfeng wrote: Hi, I'm newbie to Numpy. When reading tutorials at http://www.scipy.org/Tentative_NumPy_Tutorial http://www.scipy.org/Tentative_NumPy_Tutorial, I found a snippet about addition of two arrays with different shape, Does it make sense? If array shapes are not same, why