Antevs

Antevs

Antevs (Automatic Numerical Time-series Evaluation of Varying Sequences) is a program for correlating glacial varve sequences and similar time-series data. It was developed for the correlation of glacial varve sequences (Rayburn and Vollmer, 2013), however it includes many standard techniques for matching tree-ring sequences. The program uses Fourier analysis, or optionally curve fitting algorithms such as cubic splines, to remove trends and to normalize the series for comparison. The resulting series are correlated using cross-correlation techniques to identify potential matches. Editing capabilities allow series renumbering once an unknown series is correlated with a known chronology.

Antevs includes techniques for matching tree-ring sequences, and is used extensively in undergraduate student and other research projects in John Rayburn's varve and tree-ring laboratory at SUNY New Paltz. It can convert fles between various tree-ring formats, and includes routines for reading the Velmex UniSlide digital readout used for tree-ring measurements. Antevs is available for Macintosh, Windows, and Linux. Currently testing is done on OS X 10.6, 10.8, Windows XP, and Linux Ubuntu. User input is appreciated to improve operation on various platforms, feedback from users greatly is appreciated, and will likely result in fixes and new features.

Antevs is written by Frederick W. Vollmer. It is free software, but may not be redistributed or posted online without the author's permission. It may only be distributed as the released compressed file package with all included files. Any significant usage, such as a resulting presentation or publication, should include attribution to the program and author. This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. Please read the accompanying ReadMe file for additional information.

Versions

Antevs is available for Macintosh, Windows, and Linux. Currently testing is done on OS X 10.6, 10.8, Windows XP, and Linux Ubuntu. Current versions require a minimum of Macintosh OS X 10.5 Intel or Windows 32 XP.

Example Correlation

Correlogram A) Hudson and Connecticut River Valley raw (top) and detrended (bottom) North American Varve Chronology data (NAVC, see link on sidebar). The raw data is detrended using a 16 term Fourier filter to remove long wavelength variations, and standardized to account for thickness variations between proxmal and distal varves.

B) Correlogram produced by cross-correlation of the detrended data in A. The correlogram shows a spike corresponding to a match at 0 years offset, with a correlation of r = 0.64, and significance t = 9.57.

Modified from Rayburn and Vollmer, 2013.