dct2D

This function calculates the (orthonormal) discrete cosine
transformation for an image and returns thresholded DCT coefficients
using the C-library <code>fftw3</code> (see <a href="http://www.fftw.org/">http://www.fftw.org/</a>).

internal

Calculate a multivariate functional principal component analysis
for data observed on different dimensional domains. The estimation algorithm
relies on univariate basis expansions for each element of the multivariate
functional data (Happ & Greven, 2018) <doi:10.1080/01621459.2016.1273115>.
Multivariate and univariate functional data objects are
represented by S4 classes for this type of data implemented in the package
'funData'. For more details on the general concepts of both packages and a case
study, see Happ-Kurz (2020) <doi:10.18637/jss.v093.i05>.

Clara Happ-Kurz

MFPCA

Multivariate Functional Principal Component Analysis for Data
Observed on Different Dimensional Domains

dct2D function

<dl><dt>image</dt>
<dd>An image (a 2D matrix with real values).</dd>
<dt>qThresh</dt>
<dd>A numeric with value in \([0,1]\), giving the quantile
for thresholding the coefficients. See <code>dctBasis2D</code> for
details.</dd></dl>

Arguments

If the C-library <code>fftw3</code> is not available when
 the package <code>MFPCA</code> is installed, this function is disabled an
 will throw an error. For full functionality install the C-library
 <code>fftw3</code> from <a href="http://www.fftw.org/">http://www.fftw.org/</a> and reinstall
 <code>MFPCA</code>. This function has not been tested with
 ATLAS/MKL/OpenBLAS.

Warning

This function calculates the (orthonormal) discrete cosine
transformation for an image and returns thresholded DCT coefficients
using the C-library <code>fftw3</code> (see <a href='http://www.fftw.org/'>http://www.fftw.org/</a>).

Calculate and threshold DCT for an image — dct2D

<dl>

<dt>image</dt>
<dd>An image (a 2D matrix with real values).</dd>


<dt>qThresh</dt>
<dd>A numeric with value in \([0,1]\), giving the quantile
for thresholding the coefficients. See <code>dctBasis2D</code> for
details.</dd>

</dl>

If the C-library <code>fftw3</code> is not available when
 the package <code>MFPCA</code> is installed, this function is disabled an
 will throw an error. For full functionality install the C-library
 <code>fftw3</code> from <a href='http://www.fftw.org/'>http://www.fftw.org/</a> and reinstall
 <code>MFPCA</code>. This function has not been tested with
 ATLAS/MKL/OpenBLAS.

dct2D: Calculate and threshold DCT for an image

Description

Usage

Value

Arguments

Warning

See Also