tikz-pgf
How can I draw a previously named path in TikZ?
\documentclass[tikz]{standalone}
\usetikzlibrary{intersections}
\begin{document}
\begin{tikzpicture}
\path[name path=mypath] (0,0) -- (5,5);
%\draw[use path=mypath]; % This does not work
%\path[mypath, draw]; % This does not work
\end{tikzpicture}
\end{document}
The answer given here has a macro for use path option. Is there a solution within TikZ?
I am definitely unfamiliar with both beamer and tikz (do not quite get what the \only are supposed to do) but perhaps this could go in the direction you want:
\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{chains}
\newcounter{count}
% helper macro:
\long\def\GobToSemiColon #1;{}
\newcommand\myPicture{
\begin{tikzpicture}
\begin{scope}[start chain = going below]
\ifnum\value{count}<1 \expandafter\GobToSemiColon\fi
\ifnum\value{count}>3 \expandafter\GobToSemiColon\fi
\node[draw, rectangle, on chain] {display only when counter is between
1 and 3};
\ifnum\value{count}>-1 \expandafter\GobToSemiColon\fi
\node[draw, rectangle, on chain] {display only when counter is
negative};
\ifnum\value{count}<100 \expandafter\GobToSemiColon\fi
\ifnum\value{count}>200 \expandafter\GobToSemiColon\fi
\node[draw, rectangle, on chain] {display only if counter is between
100 and 200};
\ifnum\value{count}<3 \expandafter\GobToSemiColon\fi
\ifnum\value{count}>20 \expandafter\GobToSemiColon\fi
\node[draw, circle, on chain] {only when counter is in the range 3 to 20};
\end{scope}
\end{tikzpicture}
}
\begin{document}
\begin{frame}
\only{\setcounter{count}{-3}\myPicture}
\only{\setcounter{count}{105}\myPicture}
\only{\setcounter{count}{39}\myPicture}
\only{\setcounter{count}{2}\myPicture}
\only{\setcounter{count}{5}\myPicture}
\end{frame}
\end{document}
\draw (20,12) -- ++(2,0) -- ++(0,2) -- ++(-3,0) -- ++(45:3);
Use ++ before each new incremental coordinate to make it relative to the last one and put the pencil there.
Here's a complete example:
\documentclass{article}
\usepackage{tikz}
\begin{document}
\tikz\draw (20,12) -- ++(2,0) -- ++(0,2) -- ++(-3,0) -- ++(30:3) {[rounded corners=10pt]-- ++(5,0) -- ++(0,-6)} -- ++(-7,0) -- cycle;
\end{document}
Of course, combining this with the -| or |- path operators can simplify the code even further; the following two pieces of code produce the same result:
\tikz\draw (20,12) -- ++(2,0) -- ++(0,2) -- ++(3,0) -- ++(0,1) -- ++(1,0) -- ++(0,-3) -- ++(2,0);\par\bigskip
and
\tikz\draw (20,12) -| ++(2,2) -| ++(3,1) -- ++(1,0) |- ++(2,-3);
I don't think that defining commands in this case adds anything; in fact, I think it reduces the functionality of the existing syntax (which is already simple). The example demonstrates that you can use, for example, polar coordinates and modify (up to TikZ limitations) the path attributes midways; even if the current question doesn't require this, it's a good thing to have the possibility to do those kind of modification if they are required.
Best Answer
It is just wrong syntax. After you name a path via
[save path], you can recall it with[use path].The key
[name path]of the libraryintersectionshas totally different use. The keys[name path]and[save path]can be combined. See Section 14.22 in pgfmanual for more details.