Graphics, Figures & Tables ⇒ pgfplots | Data from *. s1p Files for Smith Diagramm

[thadrien]

Dear all,

I have found that pgfplots can plot Smith diagrams, but I have not yet found an option to directly import a *.s1p file which contains the data of such a Smith chart.

Does someone knows such option ?
Thanks a lot,
Best regards,
Hadrien

[feuersaenger]

Hi Hadrian,

An .s1p file seems to be some quite specific data format generated and/or used by 3rd party software. What is it? How is it defined?

If you have data files, pgfplots supports table format or perhaps the explicit coordinate input format. For Smith charts, it expects either untransformed complex values as input (default) or, with is smithchart cs=true, cartesian coordinates inside of the unit circle.

Best regards

Christian

[FetterChiller]

Hi!
Found this very old thread and it would have saved me hours if there would have been some examples on the usage. Here is some code with some examples on how to use this.

The following code assumes a standard s1p-File with row1 being the Frequency, row2 the real part and row3 the imaginary part:

! ListType=Lin
! Comment=PCB-Spule_N10
# MHz S RI R 50
0.1000000 -0.9712057 0.0205816
0.2333556 -0.9715719 0.0436983
0.3667111 -0.9699207 0.0673892
0.5000667 -0.9677658 0.0899401
0.6334223 -0.9641644 0.1142959
0.7667779 -0.9615511 0.1367883
0.9001334 -0.9574007 0.1607424
1.0334890 -0.9530981 0.1832266
(...)

Code: Select all

% !TeX encoding = UTF-8
% !TeX spellcheck = de_DE

\documentclass[11pt,border=0mm]{standalone}

\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}

\usepackage{tikz}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\usetikzlibrary{plotmarks}
\usepgfplotslibrary{smithchart}

%Command to create a vertical, gray, dashed line in plots
\newcommand{\vasymptote}[2][]{
	\draw [color=gray,densely dashed,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
}


\begin{document}
	\begin{tikzpicture}
		\begin{axis}[
		width=0.95\textwidth,
		height=7.5cm, %xmin=0,xmax=75,ymin=-80,
		xlabel={frequency [GHz]},ylabel={},legend pos=south west
		]
		
		
			\vasymptote {76.88} %First item-be in the bg.
			
			\addplot[color=red] table[skip first n=2, %Ignore the first two lines (comment and  ListType)
			x index=0, %in which column to find the x-values
			y expr={\thisrowno{1}} %in which column to find the y-values
			] {data/test.s1p};
			\addlegendentry{$Re(\Gamma=s_{11})$}
			
			\addplot[color=blue] table[skip first n=2, x index=0, y expr={\thisrowno{2}}] {data/test.s1p};
			\addlegendentry{$Im(\Gamma=s_{11})$}
			
			\addplot[color=black] table[skip first n=2, x index=0, y expr={(((\thisrowno{1})^2+(\thisrowno{2})^2))}] {data/test.s1p};
			\addlegendentry{$|\Gamma=s_{11}|^2$}
			
			\addplot[color=green] table[skip first n=2, x index=0, y expr={20*log10(sqrt((\thisrowno{1})^2+(\thisrowno{2})^2))}] {data/test.s1p};
			\addlegendentry{$ |\Gamma=s_{11}|\text{ in dB}$}
		
		\end{axis}
	\end{tikzpicture}

	
	\begin{tikzpicture}
		\begin{smithchart}[
		width=7.5cm,
		height=7.5cm
		]
		
			\addplot[color=red,is smithchart cs] table[skip first n=2, meta index=0, x expr={\thisrowno{1}}, y expr={\thisrowno{2}}] {data/test.s1p};
		
			\addplot+[color=blue,is smithchart cs,
			mark phase=20, %line offset for the first mark
			mark repeat=150, %lines after which to make the next mark
			mark=o,
			nodes near coords, % Place nodes near each coordinate
			point meta=explicit,
			every node near coord/.append style={
				/pgf/number format/fixed zerofill,
				/pgf/number format/precision=1
			}, % Display numbers with precision 1, e.g. 10.0, 91.2, etc
			] table[skip first n=2, meta index=0, x expr={-\thisrowno{1}}, y expr={-\thisrowno{2}} % Minus just to receive antoher graph!
			] {data/test.s1p};
		
		\end{smithchart}
	\end{tikzpicture}
	
\end{document}

The output can be seen in the attachment.

image1.png (52.2 KiB) Viewed 5820 times

[Johannes_B]

Hi and welcome, thanks for sharing you solution.

One minor thing. The real and imaginary parts are either typeset in Fraktur, or in the upright form. In the latter, it could be confused with the Reynolds number, depending on your readership. Please consider the following:

Code: Select all

\documentclass{article}
\usepackage{mathtools}
\begin{document}
$a = \Re{(a + b\mathrm i)} $ und $b = \Im{(a + b\mathrm i)}$\par
\renewcommand{\Re}{\mathrm{Re}} \renewcommand{\Im}{\mathrm{Im}}
$a = \Re{(a + b\mathrm i)} $ und $b = \Im{(a + b\mathrm i)}$
\end{document}

[FetterChiller]

Hi again.

@Johannes: Oh, thanks I've been looking for something like this. Wouldn't a renewcomand usually belong in front of begin[document]?

I also wanted to share my code for .s2p-Files and some more tricks for nice results:

Code: Select all

% !TeX encoding = UTF-8
% !TeX spellcheck = de_DE

\documentclass[11pt,border=0mm]{standalone}

\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{pgfplots}
\usepackage{tikz}
\usepackage[]{units}

% Style to select only points from #1 to #2 (inclusive)
\pgfplotsset{select coords between index/.style 2 args={
		x filter/.code={
			\ifnum\coordindex<#1\def\pgfmathresult{}\fi
			\ifnum\coordindex>#2\def\pgfmathresult{}\fi
		}
	}}
	
	

%Command to create a vertical dashed line in Plots
\newcommand{\vasymptote}[2][]{
	\draw [color=gray,densely dashed,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
}

\usepgfplotslibrary{smithchart}
%\usepgfplotslibrary[smithchart]
%\usetikzlibrary{pgfplots.smithchart}
%\usetikzlibrary[pgfplots.smithchart]
\pgfplotsset{compat=1.12}

%a4: width=21.00cm, height=29.70cm
%borders 2.5cm each side => width=16.00cm*0.95=15.2cm
%\usepackage[left=2cm, right=1cm, top=1cm, bottom=1cm]{geometry}
	
\begin{document}

	\begin{tikzpicture}
	\begin{axis}[
	title=\text{$N=10$ PCB-Spule mit Anpassungsnetzwerk},
	width=15.2cm, height=8cm,
	ymin=-18, xmin=0,xmax=200,ymax=0,
	xlabel={$f$ [MHz]},ylabel={Amplitude [dB]},legend pos=south west]
	
	\vasymptote {84.1} %Als erstes, damit im Hintergrund!
	
	\addplot[color=blue] table[skip first n=2, x index=0, y expr={20*log10(sqrt((\thisrowno{1})^2+(\thisrowno{2})^2)}] {../data/VNAS/PCB/Neu/PCB-Spule-N10-2015-05-22.s1p};
	\addlegendentry{$s_{11}$, Ohne Anpassung}
	
	\addplot[color=red] table[skip first n=2, x index=0, y expr={20*log10(sqrt((\thisrowno{1})^2+(\thisrowno{2})^2))}] {../data/VNAS/PCB/Neu/N10/2/n10-anp4.1.2015-05-28.s1p};
	\addlegendentry{$s_{11}$, impedanzangepasst}
	
	\addplot[color=green] table[skip first n=2, x index=0, y expr={20*log10(sqrt((\thisrowno{3})^2+(\thisrowno{4})^2))}] {../data/VNAS/PCB/Neu/N10/2/n10-anp4.1.2015-06-02.s2p};
	\addlegendentry{$s_{21}$, impedanzangepasst}
	
	\end{axis}
	\end{tikzpicture}


\end{document}

Results in:

Code see above.

v3-gamma.png (8.95 KiB) Viewed 5663 times

And

Code: Select all

% !TeX encoding = UTF-8
% !TeX spellcheck = de_DE

\documentclass[11pt,border=0mm]{standalone}

\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{pgfplots}
\usepackage{tikz}
\usepackage[]{units}


% Style to select only points from #1 to #2 (inclusive)
\pgfplotsset{select coords between index/.style 2 args={
		x filter/.code={
			\ifnum\coordindex<#1\def\pgfmathresult{}\fi
			\ifnum\coordindex>#2\def\pgfmathresult{}\fi
		}
	}}
	
	

%Command to create a vertical dashed line in Plots
\newcommand{\vasymptote}[2][]{
	\draw [color=gray,densely dashed,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
}

\usepgfplotslibrary{smithchart}
\pgfplotsset{compat=1.12}

%a4: width=21.00cm, height=29.70cm
%borders 2.5cm each side => width=16.00cm*0.95=15.2cm
%\usepackage[left=2cm, right=1cm, top=1cm, bottom=1cm]{geometry}
	
\begin{document}

	\begin{tikzpicture}
	\begin{smithchart}[
		title=Imdepedanz Smith-Diagramm zweier PCB-Spulen,
	width=15.2cm,
%	smithchart mirrored=false, %admittance vs impedance smith graph
%	yticklabel around circle*, %around vs in
	show origin=true,
	]

	
		\addplot+[color=blue, line width=0.4mm, is smithchart cs,
		mark phase=12, %line offset for the first mark
		mark repeat=100, %lines after which to make the next mark
		mark=x,
%		nodes near coords, % Place nodes near each coordinate
%		point meta=explicit,
%		every node near coord/.append style={
%			anchor=-90, % angle for the label
%			/pgf/number format/fixed zerofill,
%			/pgf/number format/precision=1
%		}, % Display numbers with precision 1, e.g. 10.0, 91.2, etc
		] table[skip first n=2, select coords between index={619}{643}, meta index=0, x expr={\thisrowno{1}}, y expr={\thisrowno{2}} % Minus just to receive antoher graph!
		]  {../data/VNAS/PCB/Neu/PCB-Spule-N10-2015-05-22.s1p};
		\addlegendentry{Ohne Anpassung}
		
		
		\addplot+[color=red, line width=0.4mm, is smithchart cs,
		mark phase=12, %line offset for the first mark
		mark repeat=100, %lines after which to make the next mark
		mark=o,
		%		nodes near coords, % Place nodes near each coordinate
		%		point meta=explicit,
		%		every node near coord/.append style={
		%			anchor=-90, % angle for the label
		%			/pgf/number format/fixed zerofill,
		%			/pgf/number format/precision=1
		%		}, % Display numbers with precision 1, e.g. 10.0, 91.2, etc
		] table[skip first n=2, select coords between index={619}{643}, meta index=0, x expr={\thisrowno{1}}, y expr={\thisrowno{2}} % Minus just to receive antoher graph!
		]  {../data/VNAS/PCB/Neu/N10/2/n10-anp4.1.2015-05-28.s1p};
		\addlegendentry{Mit Impedanzanpassung}
		
		%The rest of the graph in lighter colors
		\addplot[color=red!40!white,is smithchart cs] table[skip first n=2, select coords between index={0}{619},x expr={\thisrowno{1}}, y expr={\thisrowno{2}}] {../data/VNAS/PCB/Neu/N10/2/n10-anp4.1.2015-05-28.s1p};
		\addplot[color=red!40!white,is smithchart cs] table[skip first n=2, select coords between index={643}{2000},x expr={\thisrowno{1}}, y expr={\thisrowno{2}}] {../data/VNAS/PCB/Neu/N10/2/n10-anp4.1.2015-05-28.s1p};
		\addplot[color=blue!40!white,is smithchart cs] table[skip first n=2, select coords between index={0}{619},x expr={\thisrowno{1}}, y expr={\thisrowno{2}}] {../data/VNAS/PCB/Neu/PCB-Spule-N10-2015-05-22.s1p};
		\addplot[color=blue!40!white,is smithchart cs] table[skip first n=2, select coords between index={643}{2000},x expr={\thisrowno{1}}, y expr={\thisrowno{2}}] {../data/VNAS/PCB/Neu/PCB-Spule-N10-2015-05-22.s1p};
	
	
	
	\end{smithchart}
	\end{tikzpicture}

\end{document}

Results in:

Code see above.

v3-smith.png (93.31 KiB) Viewed 5663 times

I know this code is not that well documented, but I hope it helps anyway.

Now I come to another thing: Admittance Smith Charts. Though they seem a little buggy, I got this working:

Code: Select all

% !TeX encoding = UTF-8
% !TeX spellcheck = de_DE

\documentclass[11pt,border=0mm]{standalone}

\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{pgfplots}
\usepackage{tikz}
\usepackage[]{units}


% Style to select only points from #1 to #2 (inclusive)
\pgfplotsset{select coords between index/.style 2 args={
		x filter/.code={
			\ifnum\coordindex<#1\def\pgfmathresult{}\fi
			\ifnum\coordindex>#2\def\pgfmathresult{}\fi
		}
	}}
	
	
	
	%Command to create a vertical dashed line in Plots
	\newcommand{\vasymptote}[2][]{
		\draw [color=gray,densely dashed,#1] ({rel axis cs:0,0} -| {axis cs:#2,0}) -- ({rel axis cs:0,1} -| {axis cs:#2,0});
	}
	
	\usepgfplotslibrary{smithchart}
	
	%a4: width=21.00cm, height=29.70cm
	%borders 2.5cm each side => width=16.00cm*0.95=15.2cm
	%\usepackage[left=2cm, right=1cm, top=1cm, bottom=1cm]{geometry}
	
	\begin{document}


\begin{tikzpicture}[]
% First, the Admittance chart:
\begin{smithchart}[
	title=\text{Imdepedanz und Admittanz Smith-Diagramm zweier PCB-Spulen},
	smithchart mirrored=true,
	xticklabel shift=-19pt,
	grid style={blue},
	ticklabel style={blue},
	width=15.2cm,
	xtick={0.2,0.5,1,2,5},
	ytick={0,0.2,0.5,1,2,5,-0.2,-0.5,-1,-2,-5},
	xgrid each nth passes y={2},
	ygrid each nth passes x={2},%ytick align=center,
	ytick align=center,
	yticklabel style={
		rotate=180,
	},
]

\end{smithchart}


% Second, overlay the impedance chart:
\begin{smithchart}[
	show origin,
	grid style={red},
	ticklabel style={red},
	width=15.2cm,
	xtick={0.2,0.5,1,2,5}, %,0.1,0.3
	ytick={0,0.2,0.5,1,2,5,-0.2,-0.5,-1,-2,-5},
	xgrid each nth passes y={2},
	ygrid each nth passes x={2},
]

\addplot+[color=green, line width=0.4mm, is smithchart cs,
mark phase=12, %line offset for the first mark
mark repeat=100, %lines after which to make the next mark
mark=o,
%		nodes near coords, % Place nodes near each coordinate
%		point meta=explicit,
%		every node near coord/.append style={
%			anchor=-90, % angle for the label
%			/pgf/number format/fixed zerofill,
%			/pgf/number format/precision=1
%		}, % Display numbers with precision 1, e.g. 10.0, 91.2, etc
] table[skip first n=2, select coords between index={619}{643}, meta index=0, x expr={\thisrowno{1}}, y expr={\thisrowno{2}} % Minus just to receive antoher graph!
]  {../data/VNAS/PCB/Neu/PCB-Spule-N20-2015-05-22.s1p};
\addlegendentry{$N=20$}


\addplot+[color=orange, line width=0.4mm, is smithchart cs,
mark phase=12, %line offset for the first mark
mark repeat=100, %lines after which to make the next mark
mark=x,
%		nodes near coords, % Place nodes near each coordinate
%		point meta=explicit,
%		every node near coord/.append style={
%			anchor=-90, % angle for the label
%			/pgf/number format/fixed zerofill,
%			/pgf/number format/precision=1
%		}, % Display numbers with precision 1, e.g. 10.0, 91.2, etc
] table[skip first n=2, select coords between index={619}{643}, meta index=0, x expr={\thisrowno{1}}, y expr={\thisrowno{2}} % Minus just to receive antoher graph!
]  {../data/VNAS/PCB/Neu/PCB-Spule-N10-2015-05-22.s1p};
\addlegendentry{$N=10$}

\end{smithchart}

\end{tikzpicture}


\end{document}

Results in:

Code see above.

smith_ad_im.png (45.41 KiB) Viewed 5663 times

Please note that, as far as I know, the plus/minus sign of the admittance chart is wrong.


If you have any questions about this code (please only about the code, since my knowledge of LaTex is very limited), you can contact me via master (youknowwhat) aypac.de

[Johannes_B]

There are certain places where it completely fine to redefine a command within documents. Here i had to do, or nobody would have seen any changes