Version 1.1.1 (stable) of the Time2 Library released

A new version of the Time2 Library is available at http://time2.sourceforge.net/ and http://agent.ch/timeseries/t2/.

This release brings improved time comparisons. Previously it was not possible to compare times from different domains. Now, when domain differs, times are converted automatically.

When resolutions differ, the time with the lowest resolution is converted to the one with the highest resolution. For example comparing a Day to a Year will compare the day to the implicit default day of the year (which is January 1).

When resolutions do not differ, the times are converted to the unrestricted time domain for their resolution. For example a Workday and a ThirdFriday are both converted to a Day before comparing.

These semantics are not meaningful for all possible time domains. Users of "exotic" time domains should consider writing a subclass of Time2 and override the compareTo method.

StockChart: combining the Time2 Library with JFreeChart

A demo package for the Time2 library was released on September 1. It includes StockChart, a program to create price and volume charts for stocks. For this it relies heavily on JFreeChart, a flexible and powerful Java library for drawing charts. Charts can be saved as PNG images or as vector graphics in SVG files, thanks to Apache Batik.

The demo uses example files from Foo & Bar, Inc (trading symbol FBI), a company invented for the occasion. Here is a PNG chart produced by the demo:

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Clicking on the image shows the SVG version of the chart. If your browser supports SVG (like Firefox) you will be able to scale the image by resizing the window without reducing the picture quality.

The demo can be downloaded from SourceForge or from the project website.

As noted in the chart title, FBI quotes have not been adjusted for stock splits.
The halving of the price on March 18 looks suspiciously like a 2:1 ("two for one") split. A future version of the demo will take care of this problem.

Version 1.1.0 (stable) of the Time2 Library released

A new version of the Time2 Library is available at http://time2.sourceforge.net/ and http://agent.ch/timeseries/t2/. I have clarified the rule on nulls. In one sentence, it is illegal to put a null into a time series unless null was defined as the representative of missing values for the type. The rule was already present in previous versions, but it is now better documented, and also covers Filler callbacks.

Unlike announced in my previous post, the new version number is 1.1.0 and not 1.0.1. Increasing the medium version number signals the presence of incompatible modifications, in this case the addition of a throws clause to two (rarely used) methods of TimeIndexable. Details are available in the release notes included in the software.

With this release, the software leaves beta status and is now stable.

Coming soon is a little demo of time series with graphics!

Version 1.0.0 (beta) of Time2 Library released

A slightly modified version of the Time2 Library is available at http://time2.sourceforge.net/ and http://agent.ch/timeseries/t2/. I have added a README file and release notes. The names of distribution files now include version numbers.

Version 1.0.1 is expected for next week. It will come without the "beta" qualifier.

Welcome to the Time Series Software blog !

This blog is for notes and short articles about the Time2 Library, a piece of Java software I wrote and released ten days ago as an open source project. There will also be more general material related to time series software and applications.