#if defined(__FreeBSD__) || (defined(_WIN32) && !defined(__GNUC__)) || defined(__sun__)
/* what's this, we have no round function either? */
static double round(double num)
{
  return (num >= 0) ? floor(num + 0.5) : ceil(num - 0.5);
}
#endif
 

However 'round' is defined in FreeBSD and has been since FreeBSD 5.3 (according to the manual page). The fix is simple, just remove the 'defined(__FreeBSD__) ||' part of the '#if' and you should be fine. Now you can 'easy_install .' psycopg2.

PS: I'd tried to raise a ticket but http://www.initd.org/ trac seems to have been down for ages.

What gets started is handled by a program called SystemStarter. On boot it looks through /Library/StartupItems for folders. Inside those folders it looks for a script with the same name as the folder and a plist called StartupParameters.plist.

So as super user:

cd /Library/StartupItems/
mkdir PostgreSQL
touch PostgreSQL/PostgreSQL
touch PostgreSQL/StartupParameters.plist
 

Now we need to fill in the details. In PostgreSQL/PostgreSQL enter:

#!/bin/sh
 
sudo -u postgres /usr/local/pgsql/bin/pg_ctl -D /usr/local/pgsql/data -l /usr/local/pgsql/data/logfile start

This is a long line, but it's basically running postgres (via pg_ctl) as the user postgres. You'll need to change this to the whatever user you run postgres as and where ever your install of postgres is. I've used the standard names and directories so it's likely this will work for you too.

Now lets look at the plist. This file contains information for SystemStarter about when to start postgres, what postgres needs and provides and any messages to print to log files:

 
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist SYSTEM "file://localhost/System/Library/DTDs/PropertyList.dtd">
<plist version="0.9">
<dict>
        <key>Description</key>
        <string>PostgreSQL</string>
        <key>Messages</key>
        <dict>
                <key>start</key>
                <string>Starting PostgreSQL</string>
                <key>stop</key>
                <string>Stopping PostgreSQL</string>
        </dict>
        <key>OrderPreference</key>
        <string>None</string>
        <key>Provides</key>
        <array>
                <string>PostgreSQL</string>
        </array>
</dict>
</plist>
 

You can test your new settings by typing sudo SystemStarter -n -D, fix any error messages, reboot and you should have postgres all the time

dazza@macpro:~>history|awk '{a[$2]++ } END{for(i in a){print a[i] " " i}}' |sort -rn|head
96	svn
85	python
44	nosetests
40	./start-tgmetalinfo.py
37	ssh
28	tgenv
20	mate
16	cd
14	curl
13	ls
 

that's a bit weird. I do a lot of svn as I merge from development to release. I'm surprised (and pleased) to see nosetests (unit test suite) being called so frequently. tgenv is an alias I have for setting up my workingenv for TurboGears (I have many different version of turbogears installed). mate is the command line call to TextMate (text editor) from the current directory. I think the curls are there from debugging calls to AWS (Amazon Web Services).

Email Standards Project - Gmail Grimaces from Mathew Patterson on Vimeo.

I should point out that I came across this video when reading Make Magazines RSS Feed.

For me graphs allow me to unlock the huge potential of the human mind to see data. Numbers are abstract but graphs are somehow more real, more tangible. There are huge areas of the brain devoted to image and pattern recognition so I see no reason to ignore them with abstract data sets.

So when Webb Alert put me on to this TED talk I was really pleased to see graphs, graphs and oh yes animating graphs.

On an important note Hans Rosling uses his software to graph statistics for the third world and succeeds in changing my opinion on the nature of first and third worlds.

Here he is in 2006 with his graphs

and in 2007 with more graphs, more animated fun and good news about the opening of statistics about us (and mostly paid for by us as well)

A friend of mine coincidentally asked me if I knew anything about a provider he was thinking of joining. He started to bemoan his provider and the ancient wiring in his london flat. So I replied and tried not to think about my problems. As often happens I couldn't stop thinking of my own problems! I stumbled upon RouterStats. It's a cool little win32 app that basically knows how to read you routers stats page and display a little graph. I ran it on my mac using VMWare Fusion and sure enough it showed my modems 'noise ratio' getting lower and lower toward the magic 6db mark where most routers just give up and drop their ADSL connection.

A this point I decided that I couldn't be bothered to run this App (and a resident copy of windows JUST so I could look at my router stats. So I turned to python to scrape my router page

 
#script to scrape the stats from a Netgear DG834GT
import urllib2
import re
from BeautifulSoup import BeautifulSoup
from time import sleep
from datetime import datetime
 
base_path="http://192.168.1.1/"
monitor_page='stattbl.htm'
username='admin'
password = 'password'
top_level_url = base_path
 
#register an opener with urllib2 which knows how to respond to basic
#authentication requests from a webserver
password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
password_mgr.add_password(None, top_level_url, username, password)
handler = urllib2.HTTPBasicAuthHandler(password_mgr)
opener = urllib2.build_opener(handler)
urllib2.install_opener(opener)
 
#re to extract the number section from a string in the form xxx.xx db
dbre=re.compile(r"(?P<num>[\d\.]+)\s*db")
 
#for ever, ask for the stats page, extract the data and print it,
#it's  not pretty code but I am scraping a bloody router stats
#page so WHO CARES
while True:
    response = urllib2.urlopen(base_path+monitor_page)
    html= response.read()
    soup = BeautifulSoup(html)
    tables= soup.body.table.findAll('table')
    tds = tables[0].findAll('td')
 
    tx = tds[13].span.contents[0]
    rx = tds[14].span.contents[0]
 
    def extract(node):
        s  =dbre.match(node).group('num')
        return float(s)
 
    tds = tables[1].findAll('td')
    att_down = extract(tds[7].span.contents[0])
    att_up = extract(tds[8].span.contents[0])
 
    nm_down = extract(tds[10].span.contents[0])
    nm_up = extract(tds[11].span.contents[0])
 
    now = datetime.now()
    print now.strftime("%H:%M:%S"), "atd:", att_down, "atu:",\
        att_up, "nd:", nm_down, "nu:", nm_up, "rx:", rx, "tx:", tx
    sleep(5)
 

Every five seconds this prints out the stats for my router

13:44:18 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10138 tx: 4138
13:44:23 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10138 tx: 4138
13:44:29 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10137 tx: 4138
13:44:34 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10136 tx: 4137
13:44:39 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10135 tx: 4137
13:44:44 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10135 tx: 4137
13:44:50 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10134 tx: 4136
13:44:55 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10133 tx: 4136
13:45:00 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10132 tx: 4136
13:45:05 atd: 21.0 atu: 22.0 nd: 13.0 nu: 26.0 rx: 10131 tx: 4135

Well I left this running and guess what? When the phone rang my noise ratio dropped... and if it was already low my router dropped the connection. If I even picked up my phone the noise ratio dropped. After poking around with the wiring it turns out one of the phones in the house didn't have an ADSL filter so it was spewing noise on to the telephone line in the frequency range ADSL uses! Doh. Without the filter my best noise ratio was 9db, with the filter it never drops below 12db.

Well one of the engineers from Sun that gave birth to DTrace has done a google tech talk about DTrace and it's very interesting indeed. Highlights for me were the amazing instrumentation of Python which I will definitely use. He also muses on the lack of support for DTrace on linux and tries to gather a posse of developers from google to kick it off, porting DTrace to Windows and how he can't find a good book on programming.

SELECT venues.name, COUNT(gigs.venueid)
FROM venues LEFT OUTER JOIN gigs
ON gigs.venueid = venues.id
GROUP BY venues.name
ORDER BY venues.name

The JOIN joins venues and gigs where gigs.venueid equals venues.id but the LEFT OUTER statement makes sure that all rows in the left table (venues) appear in the output table. There is an excellent description of how joins work in wikipedia of course. Any row in the left table (venues) that doesn't 'join' anything in the right tables (gigs) is added with NULL values for right table columns. We don't really care about this because we are only SELECTing the venue name and the count of gigs that use that venue (so we don't need any potentially NULL column entries)

Anyway, how do we get this in to SQLAlchemy:

select([Venue.c.name, func.count(Gig.c.venueid)],
        from_obj=[venues_table.outerjoin(gig_table)],
        group_by=[Venue.c.name, Venue.c.id],
        order_by=[Venue.c.name]).execute().fetchall()

I learnt something pretty cool while working this out. You can ask SQLAlchemy to printout what query it is going to execute:

print select([Venue.c.name, func.count(Gig.c.venueid)],
        from_obj=[venues_table.outerjoin(gig_table)],
        group_by=[Venue.c.name, Venue.c.id],
        order_by=[Venue.c.name])

and you get

SELECT venues.name, count(gigs.venueid)
FROM venues LEFT OUTER JOIN gigs
ON venues.id = gigs.venueid
GROUP BY venues.name, venues.id
ORDER BY venues.name

which I think you can agree is basically identical to the required statement. Using this feature I could test out SQLAlchemy syntax and see if it was getting close to the raw SQL. This helped me a lot.

I think the SQLAlchemy syntax here is particularly intuitive. The keyword parameter from_obj is particularly pleasing as it really describes what I am doing in my head. I'm taking the venue name and it's count from the set 'venues joined with gigs'. SQLAlchemy can easily work out that venues are joined to gigs by the foreign key in each gig row which referes to a venue. So there is no need for me to specify HOW to join (the ON clause in SQL).