My new project

http://farm4.static.flickr.com/3152/3108362480_9a020622cc_d.jpg

Born Saturday, a rather surprising 5 days early. A number of my friends and contacts have infants due this season, and I wish that all arrive just as safely and joyfully.

Comments

Congrats Sean!

Author: David Fawcett

Congratulations Sean! David. Mine arrived 6 weeks ago. Lots of joy, not as much sleep...

Re: My new project

Author: Sean

Congratulations to you, David! The baby boom is bigger than I knew.

Re: My new project

Author: Paul Ramsey

Congratulations! Remember, when it comes to children, 1+1 = 11. You'll soon find that the second child is an existence proof that, despite what you might think, the first child did not actually consume every iota of your free time. What a happy Christmas!

Re: My new project

Author: PhilipRiggs

Congratulations! I agree 1+1 = 11! And 1+1+1 = 111, as I found out in August!

Re: My new project

Author: Matt Giger

Congratulations, what a beautiful little girl.

Re: My new project

Author: Jachym

Congrats! We do follow our time table too ;-)

Re: My new project

Author: Jeroen Ticheler

Congratulations to you all!

Re: My new project

Author: Mateusz Loskot

Congratulations! Now, I feel I'm a bit behind my schedule ;-)

Re: My new project

Author: Dom

Congratulations Sean! I'm sure you'll have a very happy/busy Christmas this year!

Re: My new project

Author: andrea

Congratulations, she has a nice interface ;-)

Re: My new project

Author: Bryan

... and my congrats too!

Re: My new project

Author: Matt

Awesome! I second Paul--you don't really have kids unless you have more than one. Take care of the mother too!

Re: My new project

Author: Rob

Congrats Sean!

Re: My new project

Author: Normand Savard

Congratulations to both of you!

Re: My new project

Author: Sean

Thank you, all.

Re: My new project

Author: Guillaume

Welcome to that world, little pythonista ! Mine is awaited for end of January... Best wishes Sean,

Re: My new project

Author: Jeremy Cothran

Congrats! Watch them grow, they'll learn much more than we'll ever know :)

Re: My new project

Author: Allan Doyle

Having blown past 1, 11, and 111, I know a cute baby when I see one. This one's way up there. Congrats!!

Semantic web at CAA 2009

There will be a semantic web session at the 37th annual international conference on Computer Applications and Quantitative Methods in Archaeology, 22-26 March 2009 in Williamsburg, VA [CAA 2009]:

The Semantic Web: 2nd Generation Applications

Chairs: Leif Isaksen, University of Southampton, United Kingdom, and Tom Elliott, Institute for the Study of the Ancient World, New York University, USA

Abstract:

Semantic Web technologies are increasingly touted as a potential solution to the data integration and silo problems which are ever more prevalent in digital archaeology. On other hand, there is still much work to be done establishing best practices and useful tools. Now that a number of projects have been undertaken by interdisciplinary partnerships with Computer Science departments, it is time to start drawing together the lessons learned from them in order to begin creating second generation applications. These are likely to move away from (or at least complement) the monolithic and large-scale 'semanticization' projects more appropriate to the museums community. In their place we will need light-weight and adaptable methodologies more suited to the time and cash-poor realities of contemporary archaeology.

See Leif's post to the Antiquist group for details.

Why not CIDOC CRM at this time

One of my current projects, named Concordia, aims to bootstrap a graph of open, linked data for ancient world studies. Our decision to defer use of properties of the CIDOC Conceptual Reference Model (CRM) is explained in this memo.

In a nutshell: there's no existing web of CRM-linked data, and implementing the standard gives Concordia no near-term wins. Furthermore, mismatches between the CRM and currently published data mandate a level of effort and expense that cannot be borne at this time. Because the Web is an "open world", CRM details can be added in future, as needed.

Update (2008-12-13): I've received some good feedback concerning non-technical issues that keep museum data shut in and will try to write more about that next week.

Comments

Re: Why not CIDOC CRM at this time

Author: Bryan

So, this is the first time I've heard of CIDOC again ... since I found out about it. So, the bottom line is you think it's going nowhere?

Re: Why not CIDOC CRM at this time

Author: Sean

"Going nowhere" is too strong; I'm just saying that a less perfect approach might improve the linked data picture in the near term.

Get your Python 3000 geometries on

Python 3.0 is final and I've pushed my port of Shapely to GitHub: http://github.com/sgillies/shapely-3k/tree/master.

The Shapely tests depend quite heavily on Numpy, and are somewhat broken in the new project, but it seems to work:

sean@lenny:~/code/shapely-3k$ python3.0
Python 3.0 (r30:67503, Dec  4 2008, 12:17:44)
[GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from shapely.geometry import Point
>>> r = Point(0.0, 0.0).buffer(10.0).exterior
>>> r.geom_type
'LinearRing'
>>> r.length
62.806623139095088
>>> import binascii
>>> binascii.hexlify(r.wkb)
b'01020000004200000000...'

It's strings vs bytes now in Python 3.0, which is better, but demands the change in Shapely idiom shown above.

In defense of less sexy software

Two posts from the Zope world caught my eye recently. In one, Kapil Thangavelu writes off OpenLayers too quickly. In another, Chris McDonough cautions people like me against giving up on the ZODB.

OpenLayers is large by default, but can be made more trim. Prune away the vector and raster formats you won't need, and you can get it to a more reasonable size. It's also not true that OpenLayers must pull image tiles from a WMS or TileCache instance. It's my understanding that the EveryBlock project has written a custom image layer that fetches tiles from an HTTP server or proxy, which is what Kapil is looking for. The big imagery projects on my radar are going to involve collaborative annotation, requiring some easy digitization and drawing tools and RESTful protocols for publishing captured features. OpenLayers provides these tools.

Update (2008-12-02): Revisiting Kapil's post I see that Christopher Schmidt has already made my points. Jordan Anderson's comment has more backup for OpenLayers.

How to lay out Python project code

A few years ago, a colleague asked me how to lay out a Python project. He was asking about web projects specifically, coming from a PHP background with an established tradition of file and directory structure. I didn't have a recommendation at the time other than to follow the practices of other successful projects. As Python use increases in GIS, and shops move beyond one-off scripts to reusable packages of standard processing code designed to be distributed around their systems, more GIS developers will be asking the same question. My answer is the same, but now I recommend a particular tool for arriving at the answer: paster and Paste Script. In its author's words:

paster is a two-level command, where the second level (e.g., paster help, paster create, etc) is pluggable.

Commands are attached to Python Eggs, i.e., to the package you distribute and someone installs. The commands are identified using entry points.

Paste Script has many more features, but is worth getting for the project creation feature alone. Get it from the Python Package Index: http://pypi.python.org/pypi/PasteScript/1.7.2, or by using easy_install:

$ easy_install PasteScript

The paster program comes with one template for a basic Python package. When executed, it prompts you for package name and metadata. A package of code that put a nice wrapper around arcgisscripting could be created like this:

sean@lenny:/tmp$ paster create -t basic_package
Selected and implied templates:
  PasteScript#basic_package  A basic setuptools-enabled package

Enter project name: biarcgis
Variables:
  egg:      biarcgis
  package:  biarcgis
  project:  biarcgis
Enter version (Version (like 0.1)) ['']:
Enter description (One-line description of the package) ['']:
...
Creating template basic_package
Creating directory ./biarcgis
  Recursing into +package+
    Creating ./biarcgis/biarcgis/
    Copying __init__.py to ./biarcgis/biarcgis/__init__.py
  Copying setup.cfg to ./biarcgis/setup.cfg
  Copying setup.py_tmpl to ./biarcgis/setup.py
Running /usr/bin/python setup.py egg_info

The result:

biarcgis
|-- biarcgis
|   `-- __init__.py
|-- biarcgis.egg-info
|   |-- PKG-INFO
|   |-- SOURCES.txt
|   |-- dependency_links.txt
|   |-- entry_points.txt
|   |-- not-zip-safe
|   |-- paster_plugins.txt
|   `-- top_level.txt
|-- setup.cfg
`-- setup.py

2 directories, 10 files

Let's say your shop has a standard license and authorship policy, wants more package metadata, wants to make sure all packages have a standard test suite, or just prefers a different layout. You can write your own project templates to meet these needs. I like the Pylons wiki example.

Update (2008-12-02): Kurt Schwehr wants to know where is the ChangeLog. The basic package template doesn't provide one, perhaps because the author doesn't want to presume what you want to name your log of changes. The basic Zope and Plone templates from ZopeSkel do provide a docs directory and a HISTORY.txt file for changes. The former even provides a test suite. ZopeSkel is an example of a paster template package that a shop (or community, like Zope's) might make to standardize its Python software.

Comments

Re: How to lay out Python project code

Author: Stefano Costa

It's for sure a coincidence that I was looking for an answer to the very same question during the past 3 days, but at least it's a good one.

My concern about using PasteScript is whether it is good also for an application that has nothing to do with web projects. Would you recommend it also for a generic Python application?

Re: How to lay out Python project code

Author: Sean

I did. Paste Script's basic package template is for Python packages, not web applications.

Video, Namespacing and Zopeskel

Author: Christopher Perkins

I actually have a video on showmedo that shows how to use all this stuff, and integrate testing. http://showmedo.com/videos/video?name=2910000&fromSeriesID=291 Personally, I don't start a new Python project without a fresh virtualenv. The video is a really simple how-to on how to get started with this stuff. I also blogged about the motivation for, and how to set up a namespaced project a few months ago here: http://www.percious.com/blog/archives/13 Hope this information is useful to you. cheers. -chris

Re: How to lay out Python project code

Author: Sean

Thanks, Chris. I've been using ZopeSkel's namespace package template for my zgeo projects. I'm a virtualenv user too, yet wary of recommending it to a former Avenue programmer in a GIS shop. I did some hand waving last year about how virtualenv could potentially replace FWTools.

Re: How to lay out Python project code

Author: Sean

Do watch the video Chris made if you're new to this and curious.

The beds we make

The OGC's service architecture originated in CORBA/COM, evolved into pseudo-SOAP bindings tunneling GIS data and processes through HTTP POST, and now mandates actual SOAP bindings for new services. The OGC has never pushed anything but this particular style of architecture. To the extent that INSPIRE is guided by the OGC, how could it have chosen anything but SOAP?

REST solutions

I've tried with varying degrees of success to express a certain thesis; Aristotle Pagaltzis nails it on rest-discuss:

... Resources derive from the solution domain, not part of the problem domain. Creating resources for concepts that the solution requires is how modeling works in REST terms; they don’t have to derive from any aspect of the problem in order to be justified.

Vish gets it. The problem is that you've got a legacy database and network access to it (SOAP/W*S) sucks (no uniform interface, no caching, etc). The solution: create new web resources that interface easily and cleanly with client-side javascript. These resources don't have to map one-to-one to any particular object or method in your database or framework.

Interestingly, the quote occurs in a thread about "query resources", a notion I've blogged and which remains difficult to swallow for GIS folks.

Comments

Re: REST solutions

Author: Peter Rushforth

I like the idea of posted queries, in fact Atomojo allows posted XQuery and Sparql queries. I am curious about using posted XSLT as the content of an entry. Given the ability of XSLT to access other web resources, I'm wondering if a good pattern for an XSLT couldn't be developed which was RESTful. Cheers, Peter

Re: REST solutions

Author: Sean

I don't see why XSL couldn't be used as a representation of resources that act on other documents.