CODEWITHSUNDEEP
plotlatextikz
Überfuzz
Überfuzz

Reputation: 53

Latex - Try to muster a Bode plot

I'm trying to set up a plot with two y-axis, a Bode plot with amplitude and phase in the same diagram. I use the tikzpicture package with \begin{axis} and \addplot to overlay two graphs. Well, at least that's the idea... The issue I have is that it seems I don't have control over the graphs. I can't set fix intervals for the axis, can't control color/style of plot lines. Please point out if there's something wonky in my try to make a Bode plot. In particular, how do I set style on the lines, one dashed and one solid?

    \begin{figure}[H]
\centering
\begin{minipage}{0.9 \textwidth}

\begin{tikzpicture}

%%% AMPLITUDE
\begin{axis}[
    width=340pt,
    height=180pt,
    xlabel=Frequency,
    xmode = log,
    ylabel=Amplitude [dB],
    axis x line=bottom,
    axis y line=left,
%   xmin=10, xmax=1000000,
%   ylabel near ticks,
    legend pos= south west,
    font=\scriptsize,
    legend style={font=\scriptsize,draw=none,fill=none}
    ]


\addplot table [color=black, mark=none,dotted,y=$amp$, x=freq, font=\scriptsize]{amp.dat};
\addlegendentry{$Amplitude$ }

\end{axis}

%%% PHASE
\begin{axis}[
    width=340pt,
    height=180pt,
%   xmin=10, xmax=1000000,
    hide x axis,
    axis y line=right,
    xmode = log,
    ylabel=Phase [deg],
%   ymin=-300, ymax=-120,   
%   ylabel near ticks,
    legend pos= north east,
    font=\scriptsize,
    legend style={font=\scriptsize,draw=none,fill=none}
    ]


\addplot table [mark=none,dashed, y=$phase$, x=freq]{phase.dat};
\addlegendentry{$Phase$ }

\end{axis}

\end{tikzpicture} 





\caption{A Bode-plot of the common source gain stage.} 
\label{fig:cg_sweep}
\end{minipage}
\end{figure}

Here's some test data for the plot, if needed: https://dl.dropboxusercontent.com/u/43498716/cg_sweep.dat

Thanks!

Upvotes: 3

Views: 2074

Answers (1)

sergej
sergej

Reputation: 17999

Is this what you are trying to achieve?

enter image description here

Here is a pgfplots solution.

Example for setting the intervals: xmin=10, xmax=1000000, ymin=10, ymax=35, ...

Example for setting the plot line color and style: \addplot[red, dashed] ...

\documentclass[border=10pt]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.9}

\begin{document}

\begin{tikzpicture}
\pgfplotsset{set layers}
\begin{axis}[
    xmode=log,
    xmin=10, xmax=1000000,
    ymin=10, ymax=35,
    scale only axis,
    axis y line*=left,
    xlabel=Frequency,
    ylabel={Amplitude [dB]},
]
    \addplot[blue, solid] table[x=freq,y=$amp$] {cg_sweep.dat};
    \label{aplot}
\end{axis}
\begin{axis}[
    xmode=log,
    xmin=10, xmax=1000000,
    ymin=-290, ymax=-140,
    scale only axis,
    axis y line*=right,
    axis x line=none,
    ylabel={Phase [deg]},
]
    \addlegendimage{/pgfplots/refstyle=aplot}\addlegendentry{$Amplitude$}
    \addplot[red, dashed] table[x=freq,y=$phase$] {cg_sweep.dat};
    \addlegendentry{$Phase$ }
\end{axis}
\end{tikzpicture} 

\end{document}

Upvotes: 2

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