Drawing a tube around a function

Question

I'm looking for a way to draw a tube around a function. I already defined my function (see code below). The distance between tube and function shoulb be equal in each point -> see for example arrows in the picture below.

I'm looking just for the tube outside, the arrows are just for explanation.

\documentclass[11pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
\usepackage{pgfplots}

\begin{document}
\begin{tikzpicture}[scale = 2]
\begin{axis}[
    hide axis,
    domain=0:100,
    samples=100]

\addplot[BrickRed,domain=0:100,ultra  thick, no marks] {sin(x*5.34)+cos(x)};

\end{axis}          
\end{tikzpicture}
\end{document}

Apparently this must be a curves that has the same slope everywhere as the original curve but not the same curvature — , Jan 27 '16 at 17:47
Not immediately. I've to cancel my statement about the slope as well... — , Jan 27 '16 at 17:55
Maybe ist there the possibility to set the thickness of the function graph (red) arbitrary?? This could solve the problem. — d4rty, Jan 27 '16 at 18:02
I guess this doesn't help you, but the question reminds me of http://tex.stackexchange.com/questions/175874/how-to-make-the-length-of-a-car-moving-on-a-roller-coaster-track-remain-unchange :) — Christoph, Jan 27 '16 at 18:02
This is actually (difficult) differential geometry, involving solving a system of ordinary differential equations, in my point of view — , Jan 27 '16 at 18:04
@Christoph Looks like what I'm looking for, except the car and animation :) — d4rty, Jan 27 '16 at 18:04
Isn't there the possibility, to draw the same function really really fat and deposit it in the background? — d4rty, Jan 27 '16 at 18:16
Draw it in fat color, then a little less fat in white and then the normal thickness in color (untested) — daleif, Jan 27 '16 at 18:27
You can put \addplot[double, double distance=15pt,domain=0:100, line width=1pt, no marks] {sin(x*5.34)+cos(x)}; before your actual plot (the double key does pretty much what @daleif suggested) — Jake, Jan 27 '16 at 18:39
@Jake sorry, I took your answer. Hadn't seen in. I was looking in my own questions I had asked. Sorry — Arne Timperman, Jan 27 '16 at 18:55

score 12 · Accepted Answer · answered Jan 27 '16 at 18:53

Here you are...

\documentclass[11pt]{standalone}
\usepackage[dvipsnames]{xcolor}
\usepackage{tikz}
 \usepackage{pgfplots}
 \begin{document}
\begin{tikzpicture}[scale = 2]
\begin{axis}[
hide axis,
domain=0:100,
samples=100]

\addplot[BrickRed,domain=0:100,ultra  thick, double=brown!40,double   distance=10pt, no marks] {sin(x*5.34)+cos(x)};
\addplot[BrickRed,domain=0:100,ultra  thick, no marks] {sin(x*5.34)+cos(x)};

\end{axis}          
\end{tikzpicture}
\end{document}

Drawing a tube around a function

1 Answers1