The directional-statistics tag has no wiki summary.
1
vote
1answer
61 views
What does the abbreviation “p.e.” mean?
I came across a paper that uses the abbreviation "p.e.":
Khatri and Madria, The Von Mises-Fisher Matrix Distribution in Orientation Statistics. 1976.
It's in Section 7 on page 105. I'm including a ...
3
votes
2answers
74 views
Estimating covariance of the difference of directional distributions derived from Gaussian mixtures
Given Gaussian mixtures $X_1, X_2 \in \mathbb{R}^p$ defined as $$P(X_i = x) = \sum_s \omega^{(s)}_i \mathcal{N}(x; \mu^{(s)}_i, \Sigma_i)$$ where the superscript $(s)$ indexes the $s$-th component of ...
4
votes
0answers
130 views
How to test equality of variances with circular data
I am interested in comparing the amount of variability within 8 different samples (each from a different population). I am aware that this can be done by several methods with ratio data: F-test ...
1
vote
0answers
238 views
How do I specify priors for angle parameters in BUGS/JAGS?
I am writing a hierarchical BUGS model that involves both linear and angle variables. I want the hyper-parameters to be normally distributed, which is straight-forward for the linear variables, but ...
0
votes
1answer
276 views
Estimating kappa of von Mises distribution
Is there a way to calculate an estimate of $\kappa$ from data for the von Mises distribution?
It seems very easy to do in R, http://rgm2.lab.nig.ac.jp/RGM2/func.php?rd_id=CircStats:A1inv, but python ...
4
votes
3answers
147 views
Circular/elliptical tests for datasets with magnitude and direction
I am trying to analyse (using R) a set of r(theta) data to see if the magnitude (r) is dependent on direction (theta). I have looked at circular statistics but these only seem to deal with the ...
5
votes
1answer
508 views
Repeated measures ANOVA for circular / angular / directional data
I am looking for a test for circular data that is equivalent to linear repeated measures ANOVA (I have an experiment using human participants where the same sample of participants perform multiple ...
8
votes
1answer
160 views
Logistic regression with directional data as IV
I am looking for good references on using directional data (measure of direction in degrees) as an independent variable in regression; ideally, it would also be useful for hierarchical nonlinear ...
10
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5answers
776 views
Best distance measure to use
Context
I have two sets of data that I want to compare. Each data element in both sets is a vector containing 22 angles (all between $-\pi$ and $\pi$). The angles relate to a given human pose ...
10
votes
1answer
327 views
Intuition for higher moments in circular statistics
In circular statistics, the expectation value of a random variable $Z$ with values on the circle $S$ is defined as
$$
m_1(Z)=\int_S z P^Z(\theta)\textrm{d}\theta
$$
(see wikipedia).
This is a very ...
