Mailman 3 January 2004 - NumPy-Discussion

atan2
by Niall Dalton Jan. 28, 2004

Jan. 28, 2004

Hello, I'm using Numeric 23.1, and finding it very useful! I do need to use atan2, and a browse of the manual suggests its not available as a binary ufunc. I'm happy to add it myself if I'm correct - I'm guessing it should be simple to based on the code of one of the existing functions. Is Numeric still accepting patches, or should I consider switching to Numarray? Regards, Niall ________________________________________________________________________ This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________

2 2

Returned mail: see transcript for details
by Mailer-Daemon＠ensm-douai.fr Jan. 28, 2004

Jan. 28, 2004

The original message was received at Wed, 28 Jan 2004 13:40:10 +0100 from viruswall.ensm-douai.fr [10.1.1.22] ----- The following addresses had permanent fatal errors ----- <linda(a)public.uni-hamburg.de> (reason: 501 numpy-discussion(a)lists.sourceforge.net... Unauthorized sender) ----- Transcript of session follows ----- ... while talking to [10.1.1.1]: >>> MAIL From:<numpy-discussion(a)lists.sourceforge.net> <<< 501 numpy-discussion(a)lists.sourceforge.net... Unauthorized sender 501 5.6.0 Data format error

1 0

OTCBB: SEVI - Stock-Market Profile of the Week--
by Lorna Hoffman Jan. 27, 2004

Jan. 27, 2004

Stock Profile of the Week - NEW ISSUE: SEVI - Systems Evolution Incorporated Systems Evolution Incorporated (SEVI) is a high technology consulting firm with cutting-edge technologists and integration specialists. Its seasoned staff, which includes former lead technical officers from other organizations, possesses considerable expertise and multiple certifications in technologies from such industry leaders as Microsoft, Sybase, Oracle, and Novell, as well as innovators such as Plumtree, SAP, and Actuate. As a Microsoft Certified Solutions Provider® (MCSP), SEVI employs several Microsoft certified professionals. These individuals include Systems Engineers (MCSE), Systems Developers (MCSD), Database Administrators (MCDBA), and Trainers (MCT). SEI has extensive experience with enterprise-class Microsoft solutions, in the platform implementation of Microsoft .NET servers as well as the development of Visual BASIC and Active Server Pages (ASP). Personnel help maintain our Gold Partner status with Novell. Also, SEVI was a leader in the Java revolution. SEVI technologists were among the first Java trainers, and its developers achieved early recognition for their usage of server-based Java technologies such as SilverStream application servers and J2EE. Focused on Novell's application server technology, SEVI's Sun Java-certified personnel help maintain its Gold Partner status with Novell. No more ads: http://jampe.biz/patch/o.html?eCT Equity Essence is an independent research firm. This report is based on Equity Essence's independent analysis but also relies on information supplied by sources believed to be reliable. This report may not be the opinion of SEVI management. Equity Essence has also been retained to research and issue reports on SEVI. Equity Essence may from time to time purchase or sell SEVI common shares in the open market without notice. The information contained in this report shall not constitute, an offer to sell or solicitation of any offer to purchase any security. It is intended for information only. Some statements may contain so-called "forward-looking statements". Many factors could cause actual results to differ. Investors should consult with their Investment Advisor concerning SEVI. Copyright 2004 Equity Essence. All Rights Reserved. This newsletter was distributed by CTS. CTS was paid three thousand dollars to distribute this report. CTS is not affiiated with Equity Essence and is not responsible for newsletter content. CTS: Apartado 173-3006, Zona Franca Metro, Barreal, Heredia, Costa Rica. au ot fkkufirvrx qj zavcfdp tilj idjjezcxs hkfqrwdq gbo

1 0

Status
by istfet＠cec.eu.int Jan. 27, 2004

Jan. 27, 2004

The message contains Unicode characters and has been sent as a binary attachment.

1 0

Status
by istfet＠cec.eu.int Jan. 27, 2004

Jan. 27, 2004

The message contains Unicode characters and has been sent as a binary attachment.

1 0

cygwin problems?
by Paul F. Dubois Jan. 26, 2004

Jan. 26, 2004

A user (see below) has complained that svd and other functions hang on cygwin, with numarray and Numeric. Anyone know anything about this? Hi Paul I tried the svd of numarray, version 0.6.2, I did not download the newest version of numarray, and still the same problem happen, it hanged on my cygwin box. I've also, noticed that calculating the eigenvalues of a square matrix with Numeric also hang the python 2.3 I wonder if the problem is related.... Let me know, if you have some idea of what to do next.

2 1

Re: [Numpy-discussion] summing "sparse" 2D arrays? Results...
by Ray Schumacher Jan. 26, 2004

Jan. 26, 2004

I just realized... where() belongs to Numeric, so I need sum([Numeric.where(a < 255, a, 0) for a in y]) duh. I did just compare Numeric vs. Masked arrays: =========================================================== # test.py from MA import masked_array, sum from RandomArray import * import time seed() y = randint(240,256, (480,640,16)) start = time.time() x=masked_array(y, y>=255) maskTime = time.time() - start sum_1 = sum(x,axis=2) maskedTime = time.time() - start print sum_1.shape print sum_1 print "mask make time: " + str(maskTime) print "time using MA: " + str(maskedTime) + "\n" z = Numeric.reshape(y, (16, 480, 640)) newStart = time.time() sum_2 = sum([Numeric.where(a < 255, a, 2) for a in z]) numTime = time.time() - newStart print sum_2.shape print sum_2 print "time using Numeric: " + str(numTime) + "\n" ====================================================== Result: C:\projects\Astro>python test.py (480, 640) array (480,640) , type = O, has 307200 elements mask make time: 1.07899999619 time using MA: 3.39100003242 (480, 640) array (480,640) , type = l, has 307200 elements time using Numeric: 2.39099979401 So, MA's sum() is slightly faster, but the penalty for making a mask first is large. Now I have to figure out why I had to reshape the array for the second computation. Thanks, Ray At 09:17 AM 1/26/2004 +0100, you wrote: >On 26.01.2004, at 07:14, RJS wrote: > >>The problem: I have a "stack" of 8, 640 x 480 integer image arrays from >>a FITS cube concatenated into a 3D array, and I want to sum each pixel >>such that the result ignores clipped values (255+); i.e., if two images >>have clipped pixels at (x,y) the result along z will be the sum of the other 6. >Memory doesn't seem critical for such small arrays, so you can just do > >sum([where(a < 255, a, 0) for a in images]) Hello Konrad, I just tried: from MA import masked_array, sum from RandomArray import * seed() y = randint(240,256, (480,640,2)) print sum([where(a < 255, a, 0) for a in y]) and it errors: Traceback (most recent call last): File "test.py", line 21, in ? print sum([where(a < 255, a, 0) for a in y]) NameError: name 'where' is not defined Could you enlighten me further? I have not found a good resource for compound Numeric statements yet. Thank you, Ray

1 0

Searchable online documentation of Numeric Python
by José Fonseca Jan. 26, 2004

Jan. 26, 2004

I've made this mainly for myself, but in case anybody here finds it useful, here is the online documentation of Numeric Python with TOC/index/search navigation: http://mefriss1.swan.ac.uk/htmlhelp/php/index.php?book_id=49 There's also Python documention there if you fancy it. NOTE: The URL may go dead eventually, but until I'll arrange a way to have this documentation elsewhere, so it won't worry about that. I hope you enjoy it. Jose Fonseca

1 0

Re: [Numpy-discussion] Status of Numeric
by Tim Hochberg Jan. 26, 2004

Jan. 26, 2004

Arthur wrote: [SNIP] > Which, to me, seems like a worthy goal. > > On the other hand, it would seem that the goal of something to move > into the core would be performance optimized at the range of array > size most commonly encountered. Rather than for the extraodrinary, > which seems to be the goal of numarray, responding to specific needs > of the numarray development team's applications. I'm not sure where you came up with this, but it's wrong on at least two counts. The first is that last I heard the crossover point where Numarray becomes faster than Numeric is about 2000 elements. It would be nice if that becomes smaller, but I certainly wouldn't call it extreme. In fact I'd venture that the majority of cases where numeric operations are a bottleneck would already be faster under Numarray. In my experience, while it's not uncommon to use short arrays, it is rare for them to be a bottleneck. The second point is the relative speediness of Numeric at low array sizes is the result that nearly all of it is implemented in C, whereas much of Numarray is implemented in Python. This results in a larger overhead for Numarray, which is why it's slower for small arrays. As I understand it, the decision to base most of Numarray in Python was driven by maintainability; it wasn't an attempt to optimize large arrays at the expense of small ones. > Has the core Python development team given out clues about their > feelings/requirements for a move of either Numeric or numarray into > the core? I believe that one major requirement was that the numeric community come to a consensus on an array package and be willing to support it in the core. There may be other stuff. > It concerns me that this thread isn't trafficked. I suspect that most of the exchange has taken place on numpy-discussion(a)lists.sourceforge.net. [SNIP] -tim

6 6

simple Numarray question
by Nancy Keuss Jan. 26, 2004

Jan. 26, 2004

Hi, What do I have to include in my Python file for Python to recognize Numarray functions? For instance, in a file called hello.py I try: a = arange(10) print a[1:5] and I get the error: Traceback (most recent call last): File "C:\Python23\hello.py", line 3, in ? a = arange(10) NameError: name 'arange' is not defined Thank you, Nancy

3 2