KenMankoff

Python and wxPython

I’ve recently started developing code with the Python programming language. Prior to coding I had to install the language (Python) toolkits (wxWidgets and wxPython) and tools (py2app, py2exe, wxGlade). I have a *nix computer background so rather than downloading a binary installer I opted to build everything from source on my OS X box. It took quite a while to get it all set up correctly, so I’m documenting it here in case anyone else finds themselves in the same situation.

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Hosting Big Files on a Slow Site

Just a note and a thank you to NYU for their Coral Content Distribution Network. It allows a small bandwidth site like this to host large files that require large bandwidth. All I have to do is change links from http://kenmankoff.com/some_large.file to http://kenmankoff.com.nyud.net/some_large.file. The first viewer still has to wait while CCDN gets the file from me, but all subsequent requests for the file get automagically served from the CCDN servers, at almost zero access cost to my site, for free.

If you want to have all your data served via CCDN, add this to your .htaccess:

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} !^CoralWebPrx
RewriteCond %{QUERY_STRING} !(^|&)coral-no-serve$
RewriteRule ^(.*)$ http://www.yourdomain.com.nyud.net/$1 [R,L]

For further examples (between outsourcing just one file via HTML and the entire site via Apache) read more here and here.

Managing Papers and Sources

If you author scientific publications using LaTeX and OS X, there is a useful tool chain you should know about. Even if you write non-scientific papers in MS Word on Windows you might find something useful in this post. If you don’t write, or you already use Zotero, BibDesk, zot2bib, and LaTeXiT or EquationEditor, then you should probably skip this post.

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New Domain Name

Apologies for changing the domain name so soon after launch. I see where this blog is heading and I’ve decided to host it on a domain name I bought several years ago, http://kenmankoff.com. I chose that name because it is two things I like: Space (space) and computers (bits). Either you are reading this on that domain or this site will exist there shortly. Redirects will remain in place for a while, and then this site (fiftyfour) will be taken down, and your RSS feeds will stop working.

An Historical Climate Model

I just found some old (1973) global climate model (GCM) documentation lying around the office. The document describes the GISS GCM at some stage between the UCLA parent and Model I. Model I evolved into Model II which became the foundation for EdGCM. I have scanned the document and submitted it to the History of Atmospheric GCMs website.

It is a beautiful document describing all aspects of the GCM: Numerics and dynamics, punch cards, grid schemes, physical equations, tables and tables of variables and units, etc. These two images (click for large version) show the punchcard order for the old GCM, and the grid scheme at the poles. I like the pole graphic because it reminds me of last year when I was at the South Pole.

The oldest paper I know of that discusses human induced climate change is from 1896, by Svante Arrhenius, titled On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground (PDF, 4413KB).

@article{Arrhenius:1896b,
        Author = {Svante Arrhenius},
        Journal = {Philosophical Magazine and Journal of Science},
        Month = {April},
        Number = {41},
        Pages = {237 -- 276},
        Title = {{On the Influence of Carbonic Acid in the Air
                upon the Temperature of the Ground}},
        Volume = {5},
        Year = {1896}}

@manual{Tsang:1973,
        Author = {L. C. Tsang and R. Karn},
        Month = {October},
        Institution = {Goddard Institute for Space Studies},
        Organization = {Computer Science Corporation},
        Title = {{A documentation of the GISS nine-level
                atmospheric general circulation model},
        Year = {1973}}

The Cost of this Website

In order to have a website I have to have a computer on 24 hours a day 7 days a week. I try to be aware of my energy usage and in general try to minimize it (except for that one little habit). A webserver uses energy, but in my case it is wind powered.

If you want to calculate the cost of some electronic equipment there are some simple tools you can buy such as a Kill-a-Watt or someday the EnergyHub product line. Rather than buying yet another product, I decide to calculate the costs myself. I got the idea from http://smallnotebook.org.

You need to know two bits of information. The first is the average price per kWh on your electric bill. It should be something around 15 cents. The second is the Amps the electronic device draws. It is printed on the power brick or bottom of every product. Look for this line:

Input: 110-240V ~ 1.5A

In this example the number 1.5 is the Amps. Given those two bits of information, can calculate how much it will cost to run the device. The equation is:

A * V / 1000 * hours * cost
V is 120 in the U.S.

Plug in the numbers. This webserver uses 1.5A, time is 24/7, and NYC electric rate for wind power is 18 c/kWh. The equation becomes:

1.5A * 120V / 1000 * (24h*365d) * 18c = $283.82 per year.

Which is a bit more than I expected. Maybe even enough to end this experiment. (If you can’t read this I’ve turned it off). For comparison, the Roomba uses 0.3A and charges for 3 hour/week. The equation becomes:

0.3 * 120 / 1000 * (3*52) * 0.18 = $1.01 / yr

The old vacuum used 9A, but was used much less (maybe 10 minutes every other week) for a cost of ~$3.

The equations are simple. Figure out which devices cost you the most. If you plug it all in and the numbers don’t make sense, post in the comments below.

Old Site Transferred

I’ve transferred my old site here. Comments did not get transferred. All those posts are in the ANDRILL category if you would like to see them.

I’m not sure what else will be added here, but maybe something, someday…

ANDRILL in Google Earth

I’ve released my Google Earth layer. Your comments and suggestions and data are welcome.

The KML (download here) is a very small network access file. Load it once, save it in the Google Earth sidebar, and all updates will be available each time you launch Google Earth. You need the latest Google Earth to view this layer.

This was presented at the SCAR IASC conference in St. Petersburg, Russia, July 8-11, 2008.

@conference{Mankoff:2008SCAR,
        Author = {K. D. Mankoff and the SMS Project Science Team},
        Title = {{An ANDRILL SMS ARISE Educational Software Package:
                From a microscope in Antarctica 20 million years ago
                to a global overview 100 years in the future}},
        Organization = {SCAR / IASC Open Science Conference},
        Address = {St. Petersburg, Russia},
        Month = {July 8-11},
        Year = {2008},
        Abstract = {We present an education software product
                (Google Earth Layer) that allows exploration of the
                ANDRILL SMS project. The geospatial, micro-to-macro,
                and multi-layering capabilities of Google Earth are
                used to allow viewers to tie together concepts from a
                microscopic view to a global overview. The journey
                begins with a microscopic view of diatoms in a
                borehole under the sea under the ice in Antarctica,
                and ends with a global overview of what the climate
                might look like in the year 2100 as calculated by the
                GISS Model II GCM from EdGCM. Paleo, present,
                and future GCM scenarios are available for users to
                explore more on their own using EdGCM.}}

Offline

I'm going out in the field to help with a seismic survey. I'll be offline until I get back, which should be in a week or two. I just took a nice long shower, savoring the warm water. It'll be a while until I get to do that again…

From Antarctica

RSS Readers

Dear whoever is visiting this site,

I’m really glad you’re reading this, but it would be great if you did not come back (except to add comments). Why is that? Because there are better ways to read websites than visiting them. You should be using RSS. What is RSS? The following video should explain it.

I think email is a good analogy. You don’t contact me every day or week and say, “Hey Ken, do you have anything you want to tell me?”. I email it to your inbox if I want to say it. RSS makes websites behave similarly, and your RSS reader becomes an inbox for websites with new content.

Now that you know what RSS is, subscribe to this site, keep following along, and come back and comment sometime.

My tips for a happy RSS experience:

• Find a good RSS aggregrator (like Google Reader, or if you’re really geeky, rss2email)
• Any time you come across a site you like, subscribe
• If the site publishes more than 1 article a day, unsubscribe (RSS should make your life easier, not increase the information overload)
• If you use iGoogle then you can embed Google Reader in it