Plot few columns from table with pgfplot

Question

I am trying to plot three columns from a table with pgfplot.

I have been looking around but the solutions I have found seem not to work for me. So far it does not matter what I do, I only get one line with ticks (which I don't want).

I have checked (to name few places)

• Use multiple columns as y-axis for a plot pgfplots
• Plotting multiple values from a column from a table with PGFPLOTS

This is the current code:

\begin{figure}
  \centering
  \begin{tikzpicture}
  \begin{axis}[
  title=My first gaph,
  xlabel={$\text{Ár}$},
  ylabel={$\text{Skerðingar}$},
  ]
  \addplot+[] table {test.txt};
  \foreach \column in {1,...,3}{
  \addplot+[] table {test.txt};}
  \end{axis}
  \end{tikzpicture}
  \end{figure}

I have also tried

\begin{figure}
  \centering
  \begin{tikzpicture}
  \begin{axis}[
  title=My first gaph,
  xlabel={$\text{Ár}$},
  ylabel={$\text{Skerðingar}$},
  ]
  \addplot+[blue] table[meta=Steady] {test.txt};
  \addplot+[red] table[meta=Incr] {test.txt};
  \end{axis}
  \end{tikzpicture}
  \end{figure}

So far I am only able to make this picture

But I am trying to make something similar to this

I am fairly sure I will be able to fix the years and put corresponding legens for each line. I did change the names of each column to English to prevent errors with special characters in my language.

Finally, the table I would love to plot

Year    Steady  Incr    Random
2021    280.00  280.00  280.00
2022    289.56  284.20  333.32
2023    293.72  288.46  200.60
2024    296.16  292.79  103.47
2025    297.63  297.18  402.42
2026    298.64  301.64  387.03
2027    300.05  306.16  457.79
2028    301.38  310.76  307.06
2029    303.17  315.42  146.29
2030    305.04  320.15  245.75
2031    306.32  324.95  279.80
2032    307.75  329.83  142.60
2033    309.13  334.77  304.65
2034    310.46  339.79  267.77
2035    311.72  344.89  160.39
2036    312.95  350.06  513.19
2037    314.13  355.32  261.99
2038    315.25  360.65  253.23
2039    316.35  366.06  505.29
2040    317.86  371.55  527.03
2041    318.95  377.12  367.09
2042    320.04  382.78  137.13
2043    321.14  388.52  225.11
2044    322.28  394.35  233.99
2045    323.46  400.26  186.64
2046    324.67  406.26  531.08
2047    325.91  412.36  418.04
2048    327.17  418.54  475.53
2049    328.44  424.82  318.89
2050    329.74  431.19  495.73
2051    331.11  437.66  306.65
2052    332.48  444.23  265.86
2053    333.84  450.89  253.02
2054    335.18  457.65  164.01
2055    336.52  464.52  263.51
2056    337.83  471.49  453.54
2057    339.12  478.56  478.29
2058    340.38  485.74  391.17
2059    341.60  493.02  429.69
2060    342.79  500.42  487.88
2061    345.10  507.93  373.95
2062    346.45  515.54  540.48
2063    347.80  523.28  217.49
2064    349.14  531.13  167.71
2065    350.49  539.09  373.09
2066    351.84  547.18  353.81
2067    353.18  555.39  354.63
2068    354.53  563.72  185.00
2069    355.88  572.17  426.76
2070    357.22  580.76  206.34

I am fairly sure my thesis will go faster if I get hang of pgfplot (just learned about it yesterday so please be patient). The documantation is not helping me very much, but maybe I am misunderstanding it.

This is a thesis so there are quite many packages, but here it is:

\documentclass[a4paper,12pt,twoside,BCOR=10mm]{scrbook}
% Packages
\usepackage[utf8]{inputenc}
\usepackage[icelandic]{babel}
\usepackage{t1enc}
\usepackage{graphicx}
\usepackage[intoc]{nomencl}
\usepackage{enumerate,color}
\usepackage{url}
\usepackage[pdfborder={0 0 0}]{hyperref}
\BeforeTOCHead[toc]{\cleardoublepage\pdfbookmark{\contentsname}{toc}} % Add Table of Contents to PDF "bookmark" table of contents
\usepackage{appendix}
\usepackage{eso-pic}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{longtable}
\usepackage[sf,normalsize]{subfigure}
\usepackage[format=plain,labelformat=simple,labelsep=colon]{caption}
\usepackage{placeins}
\usepackage{tabularx}
\usepackage{multirow}
\usepackage{subfigure}
% Packages used for title page layout
\usepackage{xcolor}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usepgfplotslibrary{external}
% Blue color according to HÍ corporate design
\convertcolorspec{RGB}{16,9,159}{rgb}\tmphiblue
\definecolor{hiblue}{rgb}\tmphiblue
\setlength{\parskip}{\baselineskip}
\setlength{\parindent}{0cm}
\raggedbottom
\setkomafont{captionlabel}{\itshape}
\setkomafont{caption}{\itshape}
\setkomafont{section}{\FloatBarrier\Large}
\setcapwidth{\textwidth}
%\setcapwidth[l]{\textwidth} % The original template had the [l] which leads to a warning that it gets ignored, so to reduce warnings, removed it.
\setcapindent{1em}
\usepackage{lmodern} % Use Latin Modern (instead of the default Computer Modern that is rendered using a bitmap font).
\usepackage{fixcmex} % To fix that Latin Modern large symbol math fonts has by default only one size: https://tex.stackexchange.com/a/621536
% Times new roman font instead of the standard LaTeX fonts: has not been test -- try this on your own risk
\usepackage[T1]{fontenc}
\usepackage{mathptmx}
%%%%%%%%%%%%%%%%% Configurations (Useful defaults, but OK to change %%%%%%%%%%%%%%%%%%%
\graphicspath{{figs/}} % Figures in directory figs
% Bibliography
% \usepackage[authoryear]{natbib} % Uncoment if you want to used NatBib instead of BibLaTeX (and comment the bitlatex line below)
\usepackage[backend=biber, style=authoryear]{biblatex}  % BibLaTeX used for references. 
\usepackage{csquotes} % BibLaTex wants to have context sensitive quotes
\addbibresource{references.bib} %  Name of *.bib file containing references

Answer 1

\documentclass[{article}

\usepackage[dvipsnames]{xcolor}

\usepackage{pgfplots}
\pgfplotsset{compat=newest}

\begin{document}

\begin{tikzpicture}
\pgfkeys{/pgf/number format/.cd,1000 sep={ }} % to remove the thousand separator 
\begin{axis}[
title=Title,
xlabel={x label},
ylabel={y label},
legend columns=-1, % to set one line legend
legend style={at={(0.5,-0.3)},anchor=center}, 
ymajorgrids
 ]
 \addplot[blue, thick] table [x=Year, y=Steady, col sep=space] {data.txt};
 \addplot[red, thick] table [x=Year, y=Incr, col sep=space] {data.txt};
 \addplot[Goldenrod, thick] table [x=Year, y=Random, col sep=space] {data.txt};
 \legend{Steady, Incr, Random}
 \end{axis}
\end{tikzpicture}

\end{document}

I used the color 'Goldenrod' which is better than yellow, if you you want to use it remember to load the package xcolor with the option [dvipsnames] before the pgfplots or you will have an error.