Estimates the location and scale parameters of the
 von Mises distribution by maximum likelihood estimation.

vonmises

An implementation of about 6 major classes of
statistical regression models. The central algorithm is
Fisher scoring and iterative reweighted least squares.
At the heart of this package are the vector generalized linear
and additive model (VGLM/VGAM) classes. VGLMs can be loosely
thought of as multivariate GLMs. VGAMs are data-driven
VGLMs that use smoothing. The book "Vector Generalized
Linear and Additive Models: With an Implementation in R"
(Yee, 2015) <DOI:10.1007/978-1-4939-2818-7> gives details of
the statistical framework and the package. Currently only
fixed-effects models are implemented. Many (100+) models and
distributions are estimated by maximum likelihood estimation
(MLE) or penalized MLE. The other classes are RR-VGLMs
(reduced-rank VGLMs), quadratic RR-VGLMs, doubly constrained
RR-VGLMs, quadratic RR-VGLMs, reduced-rank VGAMs,
RCIMs (row-column interaction models)---these classes perform
constrained and unconstrained quadratic ordination (CQO/UQO)
models in ecology, as well as constrained additive ordination
(CAO). Hauck-Donner effect detection is implemented.
Note that these functions are subject to change;
see the NEWS and ChangeLog files for latest changes.

Thomas Yee

VGAM

Vector Generalized Linear and Additive Models

Cleve Moler

vonmises function

von Mises Distribution Family Function — vonmises

<dl>

 <dt>llocation, lscale</dt>
<dd>Parameter link functions applied to the
 location \(a\) parameter
 and scale parameter \(k\), respectively.
 See <code>Links</code> for more choices.
 For \(k\), a log link is the default
 because the parameter is positive.
</dd>

 <dt>ilocation</dt>
<dd>Initial value for the location \(a\) parameter.
 By default, an initial value is chosen internally using
 <code>imethod</code>. Assigning a value will override
 the argument <code>imethod</code>.
</dd>

 <dt>iscale</dt>
<dd>Initial value for the scale \(k\) parameter.
 By default, an initial value is chosen internally using
 <code>imethod</code>. Assigning a value will override
 the argument <code>imethod</code>.
</dd>

 <dt>imethod</dt>
<dd>An integer with value <code>1</code> or <code>2</code> which
 specifies the initialization method. If failure
 to converge occurs
 try the other value, or else specify a value for
 <code>ilocation</code> and <code>iscale</code>.
</dd>

 <dt>zero</dt>
<dd>An integer-valued vector specifying which
 linear/additive predictors are modelled as intercepts only.
 The default is none of them.
 If used, one can choose one value from the set {1,2}.
 See <code>CommonVGAMffArguments</code> for more information.


</dd>

</dl>

Arguments

Author

Numerically, the von Mises can be difficult to fit because of a
 log-likelihood having multiple maximums.
 The user is therefore encouraged to try different starting values,
 i.e., make use of <code>ilocation</code> and <code>iscale</code>.

vonmises: von Mises Distribution Family Function

Description

Usage

Arguments

Value

Details

References

See Also

Examples