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author | Pascal Schmid <81317360+paschost@users.noreply.github.com> | 2021-05-30 15:08:15 +0200 |
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committer | GitHub <noreply@github.com> | 2021-05-30 15:08:15 +0200 |
commit | 345d5751330bc1b50cc532b8ef4634ed4f8b7560 (patch) | |
tree | 50b90c758ba9ba2312744edf98e67085be27c25f /vorlesungen/slides/8/wavelets/fourier.tex | |
parent | fixed first section content (diff) | |
parent | Merge pull request #18 from TReichlin/master (diff) | |
download | SeminarMatrizen-345d5751330bc1b50cc532b8ef4634ed4f8b7560.tar.gz SeminarMatrizen-345d5751330bc1b50cc532b8ef4634ed4f8b7560.zip |
Merge branch 'master' into part_verkehr
Diffstat (limited to '')
-rw-r--r-- | vorlesungen/slides/8/wavelets/fourier.tex | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/vorlesungen/slides/8/wavelets/fourier.tex b/vorlesungen/slides/8/wavelets/fourier.tex new file mode 100644 index 0000000..3195ec8 --- /dev/null +++ b/vorlesungen/slides/8/wavelets/fourier.tex @@ -0,0 +1,86 @@ +% +% fourier.tex -- slide template +% +% (c) 2021 Prof Dr Andreas Müller, OST Ostschweizer Fachhochschule +% +\bgroup +\begin{frame}[t] +\setlength{\abovedisplayskip}{5pt} +\setlength{\belowdisplayskip}{5pt} +\frametitle{Fourier-Transformation} +\vspace{-20pt} +\begin{columns}[t,onlytextwidth] +\begin{column}{0.48\textwidth} +\begin{block}{Aufgabe} +Gegeben: Funktion $f$ auf dem Graphen +\\ +\uncover<2->{% +Gesucht: Koeffizienten $\hat{f}$ der Darstellung in der Laplace-Basis} +\end{block} +\uncover<3->{% +\begin{block}{Definition $\chi$-Matrix} +Eigenwerte $0=\lambda_1<\lambda_2\le \dots \le \lambda_n$ von $L$ +\vspace{-10pt} +\begin{center} +\begin{tikzpicture} +\node at (-1.9,0) [left] {$\chi=\mathstrut$}; +\node at (0,0) {$\left(\raisebox{0pt}[1.7cm][1.7cm]{\hspace{3.5cm}}\right)$}; + +\fill[color=blue!20] (-1.7,-1.7) rectangle (-1.1,1.7); +\draw[color=blue] (-1.7,-1.7) rectangle (-1.1,1.7); +\node at (-1.4,0) [rotate=90] {$v_1=\mathstrut$EV zum EW $\lambda_1$\strut}; + +\fill[color=blue!20] (-1.0,-1.7) rectangle (-0.4,1.7); +\draw[color=blue] (-1.0,-1.7) rectangle (-0.4,1.7); +\node at (-0.7,0) [rotate=90] {$v_2=\mathstrut$EV zum EW $\lambda_2$\strut}; + +\fill[color=blue!20] (1.1,-1.7) rectangle (1.7,1.7); +\draw[color=blue] (1.1,-1.7) rectangle (1.7,1.7); +\node at (1.4,0) [rotate=90] {$v_n=\mathstrut$EV zum EW $\lambda_n$\strut}; + +\node at (0.4,0) {$\dots$}; + +\end{tikzpicture} +\end{center} +\end{block}} +\end{column} +\begin{column}{0.48\textwidth} +\uncover<4->{% +\begin{block}{Transformation} +$L$ symmetrisch +\\ +\uncover<5->{$\Rightarrow$ +Die Eigenvektoren von $L$ können orthonormiert gewählt werden} +\\ +\uncover<6->{$\Rightarrow$ +Koeffizienten können durch Skalarprodukte ermittelt werden:} +\uncover<7->{% +\[ +\hat{f}(k) += +\hat{f}(\lambda_k) +\uncover<8->{= +\langle v_k, f\rangle +\quad\Rightarrow\quad +\hat{f}} +\uncover<9->{= +\chi^tf} +\]} +\uncover<10->{% +$\chi$ ist die {\em Fourier-Transformation}} +\end{block}} +\uncover<11->{% +\begin{block}{Rücktransformation} +Eigenvektoren orthonormiert +\\ +\uncover<12->{$\Rightarrow$ +$\chi$ orthogonal} +\uncover<13->{ +\[ +\chi\chi^t = I +\]} +\end{block}} +\end{column} +\end{columns} +\end{frame} +\egroup |