Code: Select all
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{dsp,chains}
\DeclareMathAlphabet{\mathpzc}{OT1}{pzc}{m}{it}
\newcommand{\z}{\mathpzc{z}}
\begin{document}
\centering
% IIR filter
\begin{tikzpicture}
% Place nodes using a matrix
\matrix[row sep=6mm, column sep=6mm]
{
%--------------------------------------------------------------------
\node[dspnodeopen,dsp/label=above] (m00) {$x[n]$}; &
\node[dspnodefull] (m01) {}; &
\node[dspmixer, dsp/label=above] (m02) {$b_0$}; &
\node[dspadder] (m03) {}; &
\node[dspmixer, dsp/label=above] (m04) {$1/a_0$}; &
\node[dspnodefull] (m05) {}; &
\node[dspnodeopen,dsp/label=above] (m06) {$y[n]$}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m10) {}; &
\node[coordinate] (m11) {}; &
\node[coordinate] (m12) {}; &
\node[dspsquare] (m13) {$\z^{-1}$}; &
\node[coordinate] (m14) {}; &
\node[coordinate] (m15) {}; &
\node[coordinate] (m16) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m20) {}; &
\node[dspnodefull] (m21) {}; &
\node[dspmixer, dsp/label=above] (m22) {$b_1$}; &
\node[dspadder] (m23) {}; &
\node[dspmixer, dsp/label=above] (m24) {$-a_1$}; &
\node[dspnodefull] (m25) {}; &
\node[coordinate] (m26) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m30) {}; &
\node[coordinate] (m31) {}; &
\node[coordinate] (m32) {}; &
\node[dspsquare] (m33) {$\z^{-1}$}; &
\node[coordinate] (m34) {}; &
\node[coordinate] (m35) {}; &
\node[coordinate] (m36) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m40) {}; &
\node[dspnodefull] (m41) {}; &
\node[dspmixer, dsp/label=above] (m42) {$b_2$}; &
\node[dspadder] (m43) {}; &
\node[dspmixer, dsp/label=above] (m44) {$-a_2$}; &
\node[dspnodefull] (m45) {}; &
\node[coordinate] (m46) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m50) {}; &
\node (m51) {$\vdots$}; &
\node[coordinate] (m52) {}; &
\node (m53) {$\vdots$}; &
\node[coordinate] (m54) {}; &
\node (m55) {$\vdots$}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m60) {}; &
\node[dspnodefull] (m61) {}; &
\node[dspmixer, dsp/label=above] (m62) {$b_{M-1}$}; &
\node[dspadder] (m63) {}; &
\node[dspmixer, dsp/label=above] (m64) {$-a_{N-1}$};&
\node[dspnodefull] (m65) {}; &
\node[coordinate] (m66) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m70) {}; &
\node[coordinate] (m71) {}; &
\node[coordinate] (m72) {}; &
\node[dspsquare] (m73) {$\z^{-1}$}; &
\node[coordinate] (m74) {}; &
\node[coordinate] (m75) {}; &
\node[coordinate] (m76) {}; & \\
%--------------------------------------------------------------------
\node[coordinate] (m80) {}; &
\node[coordinate] (m81) {}; &
\node[dspmixer, dsp/label=above] (m82) {$b_M$}; &
\node[dspadder] (m83) {}; &
\node[dspmixer, dsp/label=above] (m84) {$-a_N$}; &
\node[coordinate] (m85) {}; &
\node[coordinate] (m86) {}; & \\
%--------------------------------------------------------------------
};
% Draw connections
\begin{scope}[start chain]
\chainin (m00);
\chainin (m01) [join=by dspflow];
\chainin (m02) [join=by dspconn];
\chainin (m03) [join=by dspconn];
\chainin (m04) [join=by dspconn];
\chainin (m05) [join=by dspflow];
\chainin (m06) [join=by dspflow];
\end{scope}
\begin{scope}[start chain]
\chainin (m01);
\chainin (m21) [join=by dspflow];
\chainin (m22) [join=by dspconn];
\chainin (m23) [join=by dspconn];
\chainin (m13) [join=by dspconn];
\chainin (m03) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m21);
\chainin (m41) [join=by dspflow];
\chainin (m42) [join=by dspconn];
\chainin (m43) [join=by dspconn];
\chainin (m33) [join=by dspconn];
\chainin (m23) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m41);
\chainin (m51) [join=by dspflow];
\chainin (m61) [join=by dspflow];
\chainin (m62) [join=by dspconn];
\chainin (m63) [join=by dspconn];
\chainin (m53) [join=by dspflow];
\chainin (m43) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m61);
\chainin (m81) [join=by dspline];
\chainin (m82) [join=by dspconn];
\chainin (m83) [join=by dspconn];
\chainin (m73) [join=by dspconn];
\chainin (m63) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m05);
\chainin (m25) [join=by dspflow];
\chainin (m24) [join=by dspconn];
\chainin (m23) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m25);
\chainin (m45) [join=by dspflow];
\chainin (m44) [join=by dspconn];
\chainin (m43) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m45);
\chainin (m55) [join=by dspflow];
\chainin (m65) [join=by dspflow];
\chainin (m64) [join=by dspconn];
\chainin (m63) [join=by dspconn];
\end{scope}
\begin{scope}[start chain]
\chainin (m65);
\chainin (m85) [join=by dspline];
\chainin (m84) [join=by dspconn];
\chainin (m83) [join=by dspconn];
\end{scope}
% \foreach \i [evaluate = \i as \j using int(\i+1),
% evaluate = \i as \k using int(\i+2),] in {2,4,6}
% {
% \begin{scope}[start chain]
% \chainin (m0\i);
% \chainin (m0\j) [join=by dspconn];
% \chainin (m0\k) [join=by dspline];
% \chainin (m1\k) [join=by dspconn];
% \chainin (m2\k) [join=by dspconn];
% \end{scope}
% \draw[dspconn] (m2\i) -- (m2\k);
% }
% \draw[dspflow] (m28) -- (m2X);
\end{tikzpicture}
\end{document}
- my_iir_filter.png (28.17 KiB) Viewed 4294 times
1. How can I replace the X-style multipliers with triangle-style multipliers? More like this:
I was told people here would show how to customize the tikz-dsp library?
2. The state variable labels
d_0[n], d_1[n], ... were added afterward in an image editing program. How could I make them in the document itself? Actually the lines are ugly, it would be best to fit the labels right next to the arrows they go with, like:
Small modifications such as redefinitions or some new symbol should be manageable. Also those extra annotations.