Dow Jones Industrial Average
The Dow Jones Industrial Average is a well known indicator of the overall health of the economy calculated using the current value of a variety of stocks along with a periodically adjusted divisor. The opening value of the Dow Jones Industrial Average is used as an entropy source in the Geohashing algorithm.
If you're programming a geohashing calculator, mapping service or other implementation, you'll need a source for the current and historic DJIA value. This page lists known sources and ways to access them and access restrictions.
Contents
The Internet
Conventions
In the following descriptions, tokens will be used in URLs to represent values of the date as specified by the strftime() function found in many languages. Specifically:
- %Y is the year (e.g. 1990)
- %m is the two digit month number (e.g. 03)
- %d is the two digit day number (e.g. 14)
geo.crox.net (recommended)
| geo.crox.net | |
| Date Range: | 1928/10/01 - present |
| Update Source: | djaverages.com, finance.yahoo.com and google.com/finance; some historical data from Reuters and Financial Times. |
| Update Frequency: | as soon as the data is available |
| Server Location: | two separate locations in Switzerland and France |
| Contact: | Crox |
The source can be accessed at:
http://geo.crox.net/djia/%Y/%m/%d
- Date format is quite flexible, eg %Y%m%d or %Y-%m-%d are both fine too. For compatibility with the carabiner.peeron.com source, you get a "404" http error if there is no data (however along with an error message explaining why there is no data).
- Access Restrictions: No technical restrictions, users are expected to use common sense, when in doubt, ask.
The script checks that all three sources give the same value before outputting anything. This should ensure that wrong data is never displayed (I've seen myself cases where google or yahoo temporarily had a wrong number for a short while just after 9:30.)
The source is now hosted on two different servers in two independent networks. You can either use geo.crox.net which should generally point to a working server, or alternatively use www1.geo.crox.net and fall-back to www2.geo.crox.net for maximum availability.
Please note: www1 will be down from 2013-06-07 01:45 to 2013-06-07 07:00 CEST (approximately). In the meanwhile geo.crox.net will only resolve to the www2 address.
Note that I found some discrepancies in the historical data between the different sources, but none of them affect expeditions after the algorithm was published.
I plan to make SQL dumps or CSV exports available for those wanting historical data, in the meanwhile ask me. Comments and suggestions welcome.
carabiner.peeron.com
| carabiner.peeron.com | |
| Date Range: | 1928/10/01 - present |
| Update Source: | finance.google.com, dates before 1970 from yahoo.com |
| Update Frequency: | weekdays, between 09:00 and 10:00 ET - as soon as the data is available on google. Usually up by 09:35 ET |
| Server Location: | Reston, Virginia, USA |
| Contact: | Zigdon |
The source can be accessed at:
http://carabiner.peeron.com/xkcd/map/data/%Y/%m/%d
- This is used by the reference implementation.
- Access Restrictions: There are no technical restrictions in place, but please let User:Zigdon know if you're about to use it heavily.
This source was formerly at irc.peeron.com.
finance.yahoo.com
| finance.yahoo.com | |
| Date Range: | 1928-10-01 - present |
| Update Source: | finance.yahoo.com |
| Update Frequency: | daily |
| Server Location: | Probably San Jose, CA |
| Contact: | support@yahoo.com |
The source can be accessed at:
http://ichart.finance.yahoo.com/table.csv?s=%5EDJI&a=09&b=1&c=1928&d=%m&e=%d&f=%Y&g=d&ignore=.csv
- comma-delimited file download with Date,Open,High,Low,Close,Volume,Adjusted Close
- Access Restrictions: none
During the trading day, the current opening can be accessed at
http://download.finance.yahoo.com/d/quotes.csv?s=%5eDJI&f=o
A shorter alias for this is xrl.us/djiopen. At the end of the trading day, this figure will be added to the table above along with the high/low/close etc.
Both resources use CRLF line endings, so if you are on Unix pipe this one through col(1) before trying to take the MD5, or set IFS appropriately.
Television
In areas without (instant) internet access, you need to know the current DJIA to calculate today's coordinates manually. That probably means by using a cellphone or notebook with an offline calculator.
Europe
Channel N24s teletextpage 301 shows the DJIA opening value:
SMS
Text "DJIA [date]" to +41774378210, eg:
djia 20091110
A few seconds later you should get the following message back:
DJIA opening value for 2009-11-10 is 10223.01
Not case-sensitive, so "Djia", "djia" etc. are all fine. The script is also flexible on the date format as long as it's in the Y-m-d order.
As for other sources, you always get the relevant opening value, ie if the given date is on a week-end or Dow holiday, you get the latest opening value before that date.
See also Geohashing SMS service; suggestions, comments and other feedback to User:Crox
