# Draw a path with dashed start and solid end

I want to draw a line or path with dashed line style at its begining and a solid line at the end, but in only one path (I mean, not drawing two path), something like :

\documentclass{minimal}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\draw (3,0) -- (1,0)[dashed] -- (0,0)[solid] ;
\end{tikzpicture}
\end{document}

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It's not possible to change the style of a path mid-way like this. There are ways to simulate it, though, by breaking the path into two (in such a way that you could still write something similar to the above). Would one of those be acceptable? – Loop Space Feb 16 '12 at 10:04
@AndrewStacey: You mean it can work using \draw [dashed] (3,0) -- (1,0) ; \draw (1,0) -- (0,0)[solid] ; ? Yes, but the junction of the lines is not as clean as if the line is define in one command (the first dash is closer to the solid line than to the second dash). This is the reason why I ask for a complete command... But maybe there is other ways that can solve the problem. – Sigmun Feb 16 '12 at 10:15
Maybe one could define the dash pattern carefully to get the join right. It would depend on exactly what join you wanted to achieve. – Loop Space Feb 16 '12 at 10:30
I don't understand the problem. If you use two separate commands (\draw (0,0) -- (1,0);\draw[dashed](1,0) -- (2,0);) The first dashed part is connected to the solid line. What is it you want to achieve exactly? – Roelof Spijker Feb 16 '12 at 10:43
@Sigmun Sorry I don't read correctly the question. I saw line instead of path also my answer is not really appropriated to your question. It's possible to begin the dash line with pos=... but it's very complicated Then the junction of the lines will be not very clean and it's what you want. If you want a good junction you can draw like this :\draw [dashed] (1,0) -- (3,0) ; \draw (1,0) -- (0,-1)[solid] ; You need to draw from the corner. The problem with the dash pattern is complicated. – Alain Matthes Feb 16 '12 at 16:00

If those are to be straight line segments, it couldn't get any simpler. It gets interesting with curves. Enclosed are a few examples, and I agree - it's too complicated. Clipping is the most accurate way to tell where the solid part should stop, but it requires its own scope. Fading is good for smooth transition but probably would only give headache if the path doesn't run more or less in one direction.

I'm quite sure there is a way to have a procedural stroke of the path, but I haven't found any information about that so far. I would personally enjoy a simple style that allows to easily morph the line type from start until end of a path, doing something similar to the second custom dash pattern but without all the typing. But for now, this is what I did:

\documentclass[12pt,a4paper]{minimal}
\usepackage{times}
\usepackage{tikz}

\begin{document}
\begin{tikzpicture}[line width=1.5pt]

\node at (200pt,40pt) [label=right:{2 line segments}]{};
% for straight segments this is the easiest:
%
\draw[dashed] (200pt,40pt) -- (60pt,40pt);
\draw (60pt,40pt) -- (0pt,40pt);

\node at (200pt,10pt) [label=right:{custom dash pattern}]{};
% for curves you can specify custom dash pattern, but it's cumbersome
% having to specify every singly dash untill the line becomes solid:
%
\draw[dash pattern=on 10pt off 10pt on 10pt off 10pt on 10pt off 10pt on 10pt off 10pt on 10pt off 10pt on 10pt off 10pt on 10pt off 10pt on 100pt] (200pt,10pt) .. controls (40pt,40pt)  and (90pt,-30pt) .. (0,20pt);

\node at (200pt,-10pt) [label=right:{custom dash pattern}]{};
% it does however allow for nice density modifications (but also by hand):
%
\draw[dash pattern=on 10pt off 9pt on 9pt off 8pt on 8pt off 7.3pt on 7.3pt off 6.7pt on 6.7pt off 6.3pt on 6.3pt off 5.9pt on 5.9pt off 5.4pt on 5.4pt off 5.0pt on 5.0pt off 4.0pt on 4.5pt off 3.0pt on 4.0pt off 2.4pt on 3.5pt off 1.8pt on 100pt] (200pt,-10pt) .. controls (40pt,20pt)  and (90pt,-50pt) .. (0,0pt);

\node at (200pt,-30pt) [label=right:{2 curves: dashed $+$ clipped solid}]{};
% now there's 2 paths - a long dashed one and a clipped solid one:
%
\begin{scope}
\clip (-5pt,-70pt) rectangle (60pt,5pt);
\draw (200pt,-30pt) .. controls (40pt,0pt)  and (90pt,-70pt) .. (0,-20pt);
\end{scope}
\draw[dashed] (200pt,-30pt) .. controls (40pt,0pt)  and (90pt,-70pt) .. (0,-20pt);

\node at (200pt,-50pt) [label=right:{2 curves: dashed $+$ faded solid}]{};
% for a gradient toning down of the solid line you can use fading:
%
\draw[path fading=east] (200pt,-50pt) .. controls (40pt,-20pt) and (90pt,-90pt) .. (0,-40pt);
\draw[dashed,path fading=west] (200pt,-50pt) .. controls (40pt,-20pt) and (90pt,-90pt) .. (0,-40pt);

\end{tikzpicture}
\end{document}

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The clipped solid solution doesn't allow a nice junction between solid and dashed lines: the tail of the solid line is clip vertically due to the clip command. I also improve a bit the faded solution by fading also the dashed line in the other way. – Sigmun Feb 18 '12 at 16:58
Good idea with also fading out the dashed curve. Now the left part looks smoother. As for clip, a shape different than the orthogonal rectangle would naturally give better results. – Frg Feb 18 '12 at 18:15
You right, rectangle could be something else but this becomes hard to setup automagically ! – Sigmun Feb 22 '12 at 15:25