meanspv

expmat

Computes the matrix of spherical region moments for a given model formula and a vector of radii, and uses this to
calculate the mean spherical SPV for each of the radii. The function <code>expmat</code> calculates
the matrix containing the exponents of each model factor within each model term as columns. 
Only simple formulae are allowed for. Only products of terms should be included in
calls to <code><a href="/link/I?package=vdg&version=1.2.3" data-mini-rdoc="vdg::I">I</a></code>. The power operator <code><a href="/link/%5E?package=vdg&version=1.2.3" data-mini-rdoc="vdg::^">^</a></code> should be used instead
of <code><a href="/link/sqrt?package=vdg&version=1.2.3" data-mini-rdoc="vdg::sqrt">sqrt</a></code>. Models should contain only monomial terms.

Facilities for constructing variance dispersion graphs, fraction-
of-design-space plots and similar graphics for exploring the properties of
experimental designs. The design region is explored via random sampling, which
allows for more flexibility than traditional variance dispersion graphs. A
formula interface is leveraged to provide access to complex model formulae.
Graphics can be constructed simultaneously for multiple experimental designs
and/or multiple model formulae. Instead of using pointwise optimization to
find the minimum and maximum scaled prediction variance curves, which can be
inaccurate and time consuming, this package uses quantile regression as an
alternative.

Pieter Schoonees

Variance Dispersion Graphs and Fraction of Design Space Plots

Niel le Roux

meanspv function

<dl><dt>formula</dt>
<dd>model formula</dd>
<dt>radii</dt>
<dd>numeric vector or radii at which to calculate the matrix of spherical region moments</dd>
<dt>FtF.inv</dt>
<dd>inverse of F'F, where F is the design matrix</dd>
<dt>n</dt>
<dd>integer giving the number of design runs</dd></dl>

Arguments

Author

Computes the matrix of spherical region moments for a given model formula and a vector of radii, and uses this to
calculate the mean spherical SPV for each of the radii. The function <code>expmat</code> calculates
the matrix containing the exponents of each model factor within each model term as columns. 
Only simple formulae are allowed for. Only products of terms should be included in
calls to <code><a href='https://rdrr.io/r/base/AsIs.html'>I</a></code>. The power operator <code><a href='https://rdrr.io/r/base/Arithmetic.html'>^</a></code> should be used instead
of <code><a href='https://rdrr.io/r/base/MathFun.html'>sqrt</a></code>. Models should contain only monomial terms.

Compute Mean Spherical SPV — meanspv

<dl>

<dt>formula</dt>
<dd>model formula</dd>


<dt>radii</dt>
<dd>numeric vector or radii at which to calculate the matrix of spherical region moments</dd>


<dt>FtF.inv</dt>
<dd>inverse of F'F, where F is the design matrix</dd>


<dt>n</dt>
<dd>integer giving the number of design runs</dd>

</dl>

meanspv: Compute Mean Spherical SPV

Description

Usage

Arguments

Author

References

Examples