NAME
Finance::Shares::Overview - Outline of Finance::Shares modules
DESCRIPTION
Overview
This suite aims to provide a toolbox for analysing prices of shares quoted on the world's stock exchanges. It gets the quotes from http://finance.yahoo.com, storing them in a mysql database. Calculations and tests may then be applied to the data, in an attempt to derive some meaning from the semi-chaos.
Input can be via a web interface Finance::Shares::CGI and the results are output as graphs Finance::Shares::Chart. The processing, supervised by Finance::Shares::Model focuses on applying tests to quotes for a company over a range of dates, giving an historical perspective. Of course, if the date range just covers today, the current position is evaluated. Mostly the tests compare results from calculations applied to the price or volume data. These functions are provided by several modules such as Finance::Shares::Averages and Finance::Shares::Bands.
Stock quotes are fetched using Finance::Shares::MySQL and held in a Finance::Shares::Sample object. Functions like averages or trend identifiers are applied to these data and the results used in tests. Each model can apply several tests to several samples. When the tests are run signals may be invoked highlighting interesting situations. The intention is to use these signals to drive a simulated portfolio which can be used in analysing risk.
Preparation
Whether you intend to explore the GUI interface, Model recipes or the tutorial, you need mysql working on your system with the test database that comes as standard. The tests and tutorials that come with this package (and Finance::Shares::CGI) expect a user called 'test' with 'test' as the password.
To set this up, as root, fire up the mysql client and declare the user:
# mysql Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 3 to server version: 3.23.52-Max-log
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.mysql> grant all privileges on test.* to 'test' -> identified by 'test';
Query OK, 0 rows affected (0.15 sec)NOTE: There is always a database called 'test', so you don't need to create it. However, if you've chosen to use a different name (db_name) you will need to give the command create database db_name; as well.
GUI Interface
If you are new to these modules, it might be worth looking at Finance::Shares::CGI. It provides a graphical user interface with lots of help and explanation alongside all the options. The installation is a bit more difficult as the cgi scripts have to be copied to your chosen destination manually. Also be aware that it may not work with versions later than Finance-Shares-0.07. However, it's probably easier to explore if you prefer windows. I'm not going to describe how to use the CGI interface, but here are a few hints.
There is a 'run' button at the bottom of the Model page. You will need to set up a Sample specifying the stock and dates you're interested in. The next step would be to add a Function or two like a 7 day moving average or 30 day highest/lowest values. Adding a Test on those functions will mark buy or sell signals, depending on what you've chosen. After that, it's just a matter of seeing what the different options do.
Model recipes
A script, fs_model should be available on your system. Try it out with either
fs_model --help
man fs_modelThis runs from 'recipe' files; descriptions of the model comprising mainly hash keys and values. The package directories model and stock have some example recipes and code lists. The file model/all_options is not intended to be run, but is provided as a reference to show what is available.
Tutorial
The trouble with the GUI and recipe approaches is that that's all you learn. You can only explore the paths provided and you have to start learning all over again if you want to try anything original for yourself. But it does give you some idea of how the land lies.
The lessons attempt to introduce the concepts behind the interface, and how the modules work. Hopefully you will then feel more confident about experimenting for yourself when you have seen some scripts working. The lessons available on your system can be listed with the command line:
man -k Finance::Shares::LessonAll the lesson scripts are found in the 'tutorial' directory of the Finance::Shares package. Exercises that are a little more challenging are marked with an asterisk (*).
Collecting Data
An initial development impetus was the need to have quotes available offline, so the MySQL module can be configured to work in several modes. By default, requests for quotes are served from a local cache held in a mysql database. The quotes are fetched from the internet if the cache doesn't have them. For those with fast internet access there is an online mode which bypasses the database. Alternatively, the fetch mode fills the database regardless of whether the data is already there, and offline just returns any cached quotes without looking further.
Handling PostScript
PostScript::File is used to output all charts in PostScript format. Originally this was because I couldn't find any software that printed A4 sized charts with enough accuracy and detail to scribble lines on. In practice, I don't print them out nearly as often as they are viewed on screen, but it is good to be able to do both. This doesn't sit particularly well with the web interface, but programs like pstill can convert the output to PDF easily enough. To convert chart.ps to Adobe Portable Document Format:
pstill -o chart.pdf chart.psDon't forget that most browsers can be configured to do something useful with files in application/postscript MIME format, possibly by nominating pstill as a helper program.
It is also worth investigating GhostScript which is available for a wide variety of platforms. For example, the following command (on a single line) will convert the file chart.ps to Portable Network Graphics file chart.png.
gs -q -dBATCH -sDEVICE=png16m \
-sOutputFile=chart.png chart.psGhostscript is freely available from Artifex Software, at http://ghostscript.com or from the Free Software Foundation at ftp://mirror.cs.wisc.edu/pub/mirrors/ghost/gnu/current/.
Note that gs will also work as a filter. PostScript might take a bit more work than producing graphs directly, but all the advantages of vector graphics are maintained. As well as producing the generic printer format, PostScript::File can also output EPS files for embedding directly in other documents.
Further Development
Modules for Oscillator analysis and identification of Support and Resitance trends are planned or in development. These mostly follow John J Murphy's book "Technical Analysis of the Financial Markets". Also planned is a Portfolio module for holding stock positions controlled by signals generated from Models. It would be nice if that could include some risk analysis, but that's crystal ball land.
The CGI interface was added to make the plethora of options a bit more manageable and it does provide a useable (if slow) front end. However this suite was implemented in perl to provide flexible scripting tools. For example, it should be possible to automate a series of tests to quotes for several hundred companies in order to identify the stock with the most regular patterns. I haven't included support for signals in this release because I'm still not sure what form the callback function should take. So if you have any thoughts, do email me.
AUTHOR
Chris Willmot, chris@willmot.org.uk
SEE ALSO
Have a look at the tests in the t directory of the distribution. The charts produced will give you a good idea of the kind of thing this suite does.
fs_model is the main script, using Finance::Shares::Model - see that man page for details.
Look through the function modules listed in the introduction to get an idea of the tools available. The lessons provide an introduction to these, with scripts found in the tutorial directory.
Lesson1 - Fetching quotes
Develops a short script which fetches quotes from the internet and shows how the database is used.
Lesson2 - Sampling stock quotes
This introduces the most used module, Finance::Shares::Sample and how to get a chart from the quotes fetched.
Lesson3 - Adding colour to charts
Building on the previous script, the options for Finance::Shares::Chart are explored in a little more detail. PostScript::Graph::Style objects are also introduced.
Lesson4 - Drawing moving averages
Lines are now added to the stock chart using functions from Finance::Shares::Averages as examples.
Lesson5 - Developing tests
This lesson shows how the function lines can be combined to produce signals.
Other modules
There are literally several hundred options, spread throughout the various modules. Although you are unlikely to use their objects directly, it is worth looking through the support modules to discover what options are available and how to use them:
PostScript::Graph::Paper, PostScript::Graph::Key, PostScript::Graph::Style and PostScript::File as well as Finance::Shares::MySQL.