rotations version 1.4
===================================================================

New Features - 
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*The Maxwell-Boltzmann distribution function has been added.

Minor Changes -
-------------------------------------------------------------------

* Vignette has been updated

Bug Fixes -
-------------------------------------------------------------------

* For kappa>200, the matrix-Fisher distribution is extremely difficult to sample from.
In previous versions of this package, the matrix-Fisher distribution was replaced by the 
Cayley distribution for large kappa.  Now the Maxwell-Boltzmann distribution is used 
because it agrees much more closely with the matrix-Fisher distribution than with the
Cayley distribution for large kappa.

rotations version 1.3
===================================================================

New Features - 
-------------------------------------------------------------------

* The function `discord` has been added, which computes a measure of discord for random rotations
* The previously proposed extrinsic measure of discord is included as well as the novel intrinsic measure

Minor Changes -
-------------------------------------------------------------------

* Vignette has been updated
* `tail.Q4` and `tail.SO3` have been added

Bug Fixes -
-------------------------------------------------------------------


rotations version 1.2
===================================================================

New Features - 
-------------------------------------------------------------------

* Proposal central orientation parameter values are now drawn from the distribution specified by the `type` argument in all of the Bayesian functions

Minor Changes -
-------------------------------------------------------------------

* Sampling from the von Mises Fisher and matrix Fisher distributions is now done in C++ resulting in a significant speed up
* `method` argument in `regions` function was changed from `trans` to `transformation`, a call to `match.arg()` still allows for `trans`
* `type` argument in `regions` function has been changed from `theory` to `asymptotic`

Bug Fixes -
-------------------------------------------------------------------
* A typo in the (not run) Bayes credible region example has been fixed
* `print` method for `Q4` objects now respects the `digits` option


rotations version 1.1
===================================================================


New Features - 
-------------------------------------------------------------------

* The argument `interactive' has been added to `plot.SO3' and `plot.Q4' which, when set to `TRUE', creates a sphere in 3D using `rgl' that can be manipulated by the user


Minor Changes -
-------------------------------------------------------------------

* The options for the `method` argument of the `region` functions have been changed to `"trans"` and `"direct"` to align with the current names in my dissertation.  `"trans"` is short for "transformation," which is used to access the methods based on a transformation of a directional statistics result while `"direct"`  is used for the methods that rely on theory for SO(3) directly.


rotations version 1.0
===================================================================


New Features - 
-------------------------------------------------------------------

* Vignette added that introduces the package

* Create a `plot.Q4` function that uses `plot.SO3` after casting the object to class `SO3`

Bug Fixes -
-------------------------------------------------------------------
* Updated Bayes sampling method to avoid seg faults

Major Changes -
-------------------------------------------------------------------

* The functions `SO3` and `Q4` have been deprecated.  All of their functionality has been moved to `as.SO3` and `as.Q4`

* `angle` and `axis` have been renamed `mis.angle` and `mis.axis`, respectively, to avoid naming clashes with the `graphics` package

* The `period.sep` naming convention has been adopted for all functions in package.  The functions formerly known as `sum_dist`, `exp_skew`, `cayley_kappa`, `fisher_kappa` and `vmises_kappa` are now called `rotdist.sum`, `skew.exp`, `cayley.kappa`, `fisher.kappa` and `vmises.kappa`, respectively.

* `dist` renamed to `rot.dist` to avoid clashes with `stats` package

Minor Changes -
-------------------------------------------------------------------
* Fixes in documentation for Bayes point estimation

* `print.Q4` and `print.SO3` no longer print the object class

* `print.SO3` now names the columns `R11` through `R33` to signify which element in the matrix each row corresponds to

* `is.SO3` more rigorously tests for conditions of `SO3`

* Arithmetic for `SO3` objects now is possible for samples of rotations



rotations version 0.2
===================================================================

Changes -
-------------------------------------------------------------------
* Multiple columns can be supplied to `col` in `plot` via grid.arrange.  Each requested column is identified by its axis and one legend is printed when applicable.  For example `col=c(1,3)` will print two labelled eyeballs, one for the x- and one for the z-axis.

* Quaternions are only unique up to their sign, that is if q is a quaternion the q=-q.  So `==` has be redefined such that `q==-q` will return `TRUE`.

* In 'dist' the 'method' argument now accepts the option 'extrinsic' and returns the same result had the 'projected' option been used.

New Features -
-------------------------------------------------------------------
* The `'['` operator has been redefined to maintain the `SO3` or `Q4` class of the object.

* Addition `+` and subtraction `-` have been redefined for the multiplicative group SO(3).  That is, for R1 and R2 in SO(3), R1+R2=R2R1, R1-R2=R2'R1 and -R1=R1'.  Similarly for quaternions.

* The `head` and `str` functions have been modified to properly handle objects of class `'SO3'` and `'Q4'`.

* Functions for Bayesian analysis
  * Each of the following functions requires the user to supply `type`, `tuneS`, `tuneK`, `burnin` and `B`.  These arguments  determine the transition probability form, tuning parameters for the central orientation, concentration parameter, burnin for the MCMC and total number of draws from the posterior, respectively.  Currently only `'Cayley'`, `'Fisher'` and `'Mises'` are valid options for `type`.  See the respective help files for more details.
  * The function `MCMCSO3` implements a Gibbs-within-MCMC algorithm to get draws from the posterior distributions for the concentration parameter $S$ and concentration parameter $\kappa$.  A list of four items is returned: `S` is a B-by-p matrix where each row corresponds to a draw from the posterior for the central orientation S, `kappa` is a vector of B draws from the posterior for the concentration parameter $\kappa$ and the transition probabilities for the central orientation and concentration are given by `Saccept` and `Kaccept`,respectively.
  * Bayesian point estimates for the central orientation and concentration parameter are given by `bayes.mean`.
  * Bayesian credible regions have been added to the `region` by setting `method='Bayes'`. 


rotations version 0.1
===================================================================
* First CRAN release