Antevs

Antevs

ANTEVS (Automated Numerical Time-series Evaluation of Varying Sequences) is a program for correlating glacial varve sequences, tree-rings, and other time-series data. It was developed for the correlation of glacial varve sequences (Rayburn and Vollmer, 2013), but includes standard techniques for matching tree-ring sequences. The program uses Fourier analysis, cubic splines, and other algorithms 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, joining and splitting of measurements, construction of mean chronologies, and correlation of incomplete sequences with missing data (NaN) values.

Antevs is designed to be user-friendly with a simple graphical interface, 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 between numerous data file formats, including most spreadsheet and tree-ring files. It also can interface with the Velmex Unislide digital readout system, used for digitally recording tree-ring measurements, which allows automated data collection and analysis in one integrated package.

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 User Manual file for license and additional information.

Versions

Antevs is available for Macintosh, Windows, and Linux. Currently testing is done on OS X 10.6, 10.8, Windows XP, Windows 7, and Linux Ubuntu. Feedback, feature requests, and bug reports are appreciated to improve operation on various platforms.

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.