Reference:
The circular statistics toolbox for Matlab, P. Berens and M. J. Velasco, MPI Technical Report No. 184, 2009
This document should be cited when the provided code is used. See licensing terms for details.
Contents:
circ_r Resultant vector length
circ_mean Mean direction of a sample of circular data
circ_axialmean Mean direction for axial data
circ_median Median direction of a sample of circular data
circ_std Dispersion around the mean direction (std, mardia)
circ_var Circular variance
circ_axialmean R, mean direction for axial (multi-modal) data
circ_moment Complex p-th moment
circ_dist Distances around a circle
circ_dist2 Pairwise distances around a circle
circ_confmean Confidence intervals for mean direction
circ_stats Summary statistics
circ_rtest Rayleigh's test for nonuniformity
circ_otest Hodges-Ajne test (omnibus test) for nonuniformity
circ_raotest Rao's spacing test for nonuniformity
circ_vtest V-Test for nonuniformity with known mean direction
circ_medtest Test for median angle
circ_mtest One-sample test for specified mean direction
circ_wwtest Multi-sample test for equal means, one-way ANOVA
circ_gtest Stephen's G test for equality of modal vectors
circ_symtest Test for symmetry around median angle
circ_corrcc Circular-circular correlation coefficient
circ_corrcl Circular-linear correlation coefficient
circ_clust Simple k-means clustering
circ_vmpdf Von Mises pdf
circ_randvm Draw samples from a von Mises distribution
circ_vmpar Estimate parameters of von Mises distribution
circ_r2kappa Converts mean resultant vector length to concentration parameter
circ_kappa2r Converts concentration parameter to mean resultant vector length
circ_plot Visualization for circular data
rad2ang Convert radian to angular values
ang2rad Convert angular to radian values
bessip Generic Bessel function of order p
bessi0 Bessel function of order 0
bessi1 Bessel function of order 1
All functions take arguments in radians (expect for ang2rad). For a detailed description of arguments and outputs consult the help text in the files.
References:
- E. Batschelet, Circular Statistics in Biology, Academic Press, 1981
- N.I. Fisher, Statistical analysis of circular data, Cambridge University Press, 1996
- S.R. Jammalamadaka et al., Topics in circular statistics, World Scientific, 2001
- J.H. Zar, Biostatistical Analysis, Prentice Hall, 1999
The implementation follows in most cases 'Biostatistical Analysis' and all referenced equations and tables are taken from this book, if not otherwise noted. In some cases, the other two books were preferred for implementation was more straightforward for solutions presented there.
Versions:
2006: Initial release
2008: The code has been cleaned up, some extra functionality and new tests have been added and some bugs removed. New features include confidence limits on the mean, the vtest, mtest, wwtest and corrcl commands for additional hypothesis testing and correlation analysis.
2009: Added median, otest, gtest, raotest, symtest, expanded wwtest to multi-sample testing, updated p-value formula for Rayleigh test, updated std for additional options, added stats, all functions for density estimation/distributions are new. Added Marc J. Velasco as second author.
If you have suggestions, feature requests or want to contribute code, please email us.
Disclaimer:
All functions in this toolbox were implemented with care and thoroughly tested on the examples presented in 'Biostatistical Analysis' were possible. Nevertheless, they may contain errors or bugs, which may affect the outcome of your analysis. We do not take responsibility for any harm coming from using this toolbox, neither if it is caused by errors in the software nor if it is caused by its improper application. Please email us any bugs you find.
By Philipp Berens and Marc J. Velasco, 2009
berens@tuebingen.mpg.de , velasco@ccs.fau.edu - www.kyb.mpg.de/~berens/circStat.html
Distributed under Creative Commons license Attribution-Noncommercial-Share Alike 3.0
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