From barrett at stsci.edu  Fri Mar 12 16:36:47 2004
From: barrett at stsci.edu (Paul Barrett)
Date: Fri, 12 Mar 2004 16:36:47 -0500
Subject: [AstroPy] Numarray 0.9 now on Source Forge
Message-ID: <40522D6F.20200@stsci.edu>

<x-flowed>
The latest version of numarray, version 0.9, is now on sourceforge for your 
numerical pleasure.

  -- Paul


Release Notes for numarray-0.9

Numarray is an array processing package designed to efficiently
manipulate large multi-dimensional arrays.  Numarray is modelled after
Numeric and features c-code generated from python template scripts,
the capacity to operate directly on arrays in files, and improved type
promotions.

I. ENHANCEMENTS

1. Support for "from __future__ import division"

True division has been implemented for numarray.  This means that
modules that wish to use true division can also use numarray and
numarray division will work as follows:

a. dividing any two integer arrays using "/" results in a Float32
array.

b. dividing two floating point arrays using "//" results in truncation
of the result as in:  a // b == floor(a/b).

2. C-coded array slicing

Array slicing has been re-implemented in C-code as part of the
_ndarray module.  This means faster slicing.  Thanks go to Warren
Hack, Chris Hanley, and Ivo Busko for helping debug a huge refcount
error.

3. Decreased Ufunc overhead

Ufunc execution speed has clawed and scratched its way back to where
it was around numarray-0.5.  Improvements here included optimization
of the ufunc caching, smarter thread handling, and smarter support for
subclasses.  The ufunc caching is based on a simple 20 element table
for each ufunc.

4. Faster array creation from C

Code which creates NumArrays from C (including numarray itself) can
now do so faster because the API functions have been modified to do
the array __init__ inline rather than through an expensive Python
callback.

II. BUGS FIXED / CLOSED

See
http://sourceforge.net/tracker/?atid=450446&group_id=1369&func=browse
for more details.

913781 Another memory leak in example in Chapter 12
908399 Numarray 0.7: "del a[1]" dumps core
899259 astype Int16 copy4bytes: access beyond buffer
895801 Buffer overflow in sum w/ 0-sized array
894810 MemoryError When Creating Large Arrays
890703 getnan() and getinf() failure
883124 and and operator.and respond differently
865410 Usage of __dict__
854480 Slice assignment of float to integer
839367 Overlapping slice assign fails
828941 Numarray: determinant returns scalar or array
820122 Linearalgebra2.determinant problem
817343 Sub-classing of NumArray inhibited by complex values
793336 crash in _sort.pyd
772548 Reference counting errors
683957 Adding certain arrays fails in Numarray

III. CAUTIONS

1. numarray extension writers should note that the documented use of
PyArray_INCREF and PyArray_XDECREF (in numarray) has been found to be
incompatible with Numeric and has therefore been deprecated.  numarray
wrapper functions using PyArray_INCREF and PyArray_XDECREF should
switch to ordinary Py_INCREF and Py_XDECREF.


-- 
Paul Barrett, PhD      Space Telescope Science Institute
Phone: 410-338-4475    ESS/Science Software Branch
FAX:   410-338-4767    Baltimore, MD 21218

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</x-flowed>

From owen at astro.washington.edu  Fri Mar 19 11:47:51 2004
From: owen at astro.washington.edu (Russell E Owen)
Date: Fri, 19 Mar 2004 08:47:51 -0800
Subject: [AstroPy] Numarray 0.9 now on Source Forge
Message-ID: <p06020401bc80d487afd5@[128.95.99.44]>

<x-flowed>At 11:04 AM -0500 2004-03-19, Nor Pirzkal wrote:
>	I am trying to install numarray 0.9 but cannot seem to be 
>able to install the extra Packages (MA LinearAlgebra2 etc...). I 
>think that this used to be handled by something like setupall.py in 
>the past. How should I install these?

Are you sure they aren't already installed?

I found that MA was installed automatically as part of numarray 0.8. 
I have no idea about the linear algebra stuff.

Note that the documentation was out of date in this respect (and I 
may have forgotten to submit a bug report on that).

-- Russell
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From loredo at astro.cornell.edu  Fri Mar 19 15:49:27 2004
From: loredo at astro.cornell.edu (Tom Loredo)
Date: Fri, 19 Mar 2004 15:49:27 -0500 (EST)
Subject: [AstroPy] Comprehensive python time code class?
Message-ID: <200403192049.i2JKnRL25405@laplace.astro.cornell.edu>


> I've coded a simple and not terribly comprehensive version but I'm 
> looking for something more powerful, particularly in dealing with 
> issues like different time standards & zones, high-time resolution, 
> leap seconds & years, time differences, and incrementing.  

I'm not clear on exactly what you're looking for, but mxDateTime
claims to handle time zones, daylight savings time, leap secs, etc..
It appears to use UTC.

http://www.egenix.com/files/python/mxDateTime.html

The Boost folks have a page with date/time links, including
C/C++ libraries:

http://www.boost.org/libs/date_time/doc/References.html

I don't use any of this stuff so I can't comment on its suitability.
I just happened to recall hearing of it.  I have a dim recollection
of a recent addition to the std lib that deals with dates and time,
but I may just be remembering an announcement of the latest
mxDateTime.

-Tom Loredo
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