Book contents
- Frontmatter
- Contents
- Preface to the first paperback edition
- Preface
- 1 Introduction
- 2 Descriptive methods
- 3 Models
- 4 Analysis of a single sample of data
- 5 Analysis of two or more samples, and of other experimental layouts
- 6 Correlation and regression
- 7 Analysis of data with temporal or spatial structure
- 8 Some modern statistical techniques for testing and estimation
- Appendix A Tables
- Appendix B Data sets
- References
- Index
6 - Correlation and regression
Published online by Cambridge University Press: 03 May 2011
- Frontmatter
- Contents
- Preface to the first paperback edition
- Preface
- 1 Introduction
- 2 Descriptive methods
- 3 Models
- 4 Analysis of a single sample of data
- 5 Analysis of two or more samples, and of other experimental layouts
- 6 Correlation and regression
- 7 Analysis of data with temporal or spatial structure
- 8 Some modern statistical techniques for testing and estimation
- Appendix A Tables
- Appendix B Data sets
- References
- Index
Summary
Introduction
Whereas the previous chapters have been concerned with statistical inference for a single sample of data (typically, relating to the reference direction or dispersion) and with comparison of such quantities across several samples, this chapter and the next are concerned with relationships between random variables, or the dependence of a circular random variable on another variable. Examples of the sorts of problems to be studied in this chapter are:
Example 6.1 Figure 6.1 shows 19 measurements of wind direction and ozone concentration taken at 6.00am at four-day intervals between April 18th and June 29th, 1975, at a weather station in Milwaukee. (The data are listed in Appendix B18.) It is of interest to ascertain whether there is any association between ozone concentration and wind direction.
Example 6.2 Figure 6.2 shows the orientations (θi) of the nests of 50 noisy scrub birds along the bank of a creek bed, together with the corresponding directions (ϕi) of creek flow at the nearest point to the nest. (The data are listed in Appendix B19.) The separate data sets for the nest orientations and the creek flows are shown, together with a joint data plot. The directions of creek flow suggest that the creek has a small bend in the vicinity of data collection. The joint data plot consists of a scatterplot of the values (θi, ϕi), i = 1,…, n, together with a duplicate set (θi + 360°, ϕi + 360°), i = 1,…,n (shown here in radians) to avoid difficulties due to transferring the data to the x-y plane. […]
- Type
- Chapter
- Information
- Statistical Analysis of Circular Data , pp. 135 - 168Publisher: Cambridge University PressPrint publication year: 1993