help with a plot

Question

Hi guys I wanted to do the following plot using tikz.

Can you help me replicate this picture? I'd prefer not to use pgfplots instead I'd like to use the \draw plot function. The plotted equation sounds like this $y=v_{exit}ln(M_0/m})$ .

Possible duplicate: https://tex.stackexchange.com/questions/105570 — Dr. Manuel Kuehner, Mar 27 '22 at 23:10
I would still go with pgfplots unless you have a good reason not to. — Dr. Manuel Kuehner, Mar 27 '22 at 23:17
Do you understand that "the course" has no meaning to me?! :) And if it is homework that this is maybe not the right forum or at least state it in the question if this is the case. — Dr. Manuel Kuehner, Mar 27 '22 at 23:26
A good start is the excellent manual (https://www.ctan.org/pkg/pgf). Chapter 79 "Introduction to Data Visualization" explains the concept. — Dr. Manuel Kuehner, Mar 28 '22 at 01:11

Sandy G · Answer 1 · 2022-03-28T04:31:19.637

5

Here is a TikZ solution.

The actual scale of the graph is from 0 to 5 on the x-axis and 0 to 9 on the y-axis. The labels are calculated accordingly. The xscale and yscale settings are for appearance only, so that the graph is 10cm wide (with xscale set at 2) and 7.2cm high (with y-scale set at .8). Of course you can change the values of xscale and yscale however you like to best fit your document.

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[xscale=2,yscale=.8,font=\sffamily]
\draw[gray!50] (0,9)--(0,0) (-.1,0)node[black,left]{0}--(5,0)--(5,9);
\foreach \y in {2,4,...,18}{\drawgray!50node[black,left]{\y,000}--(5,\y/2);}
\foreach \x in {0,5,...,25}{\drawgray!50node[black,below]{\x}--(\x/5,0);}
\foreach \v/\c[count=\n,evaluate=\v as \l using int(\v1000)] 
    in {1/red,1.5/orange,2/yellow,3/green,4/blue,5/violet}{
    \draw[ultra thick, \c, domain=.2:5, smooth, variable=\x] plot (\x, {.5\vln(5\x)});
    \drawultra thick, \c--(5.8,7-\n/1.5)node[black,right]{\l};
}
\end{tikzpicture}
\end{document}

edited Mar 28 '22 at 04:31

answered Mar 28 '22 at 04:20

Sandy G

42,558

+1: For clarification "actual scale is from 0 to 5" refers to the physical paper dimensions (cm by default AFAIK) AND the diagram units, correct? – Dr. Manuel Kuehner Mar 28 '22 at 04:25
1

@Dr.ManuelKuehner: Physical paper dimensions of the graph are affected by xscale and yscale. I'll try to make my explanation more clear. – Sandy G Mar 28 '22 at 04:27
1

@Dr.ManuelKuehner: I edited my response. Is it more clear now? – Sandy G Mar 28 '22 at 04:32
Very good, thanks! – Dr. Manuel Kuehner Mar 28 '22 at 04:45

score 2 · Answer 2 · answered Mar 27 '22 at 23:29

A starting point using pgfplots.
I do not plan to replicate the picture but the OP can use the code below as a start.

\documentclass[tikz]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\begin{document}

\begin{tikzpicture}
    \begin{axis}[
        xlabel = $x$,
        ylabel = {$a \cdot \ln(x)$},
        xmin = 0,
        xmax = 25,
        axis x line = bottom,
        axis y line = left,
    ]
    % Plot 1
    \addplot[
        domain = 1:25, 
        samples = 201,
        smooth,
        color = blue,
        ] {10ln(x)};
        \addlegendentry{$a = 10$}
    % Plot 2
    \addplot[
        domain = 1:25, 
        samples = 201,
        smooth,
        color = red,
        ] {20ln(x)};
        \addlegendentry{$a = 20$}

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

(https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation)

help with a plot

2 Answers2