TikZ-subfigures are not horizontally aligned

Question

I have tried to align two tikz-subfigures. For for some reason though it doesn't work completely and they are misaligned horizontally as per this screenshot.

What am I doing wrong here?

\documentclass[12pt, a4paper]{article}
\usepackage[english]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{array}
\usepackage{subcaption}
\usepackage[hmargin=1in, vmargin=1.2in]{geometry}
\usepackage[labelfont=bf]{caption}
\captionsetup{width=.98\linewidth}
\usepackage{setspace}
\setstretch{1.3}
\usepackage{pgfplots}
\usepackage{tikz}
\pgfplotsset{compat=1.18}
\begin{document}
\begin{figure}[h]
  \begin{subfigure}{\linewidth}
    \centering
    \begin{tikzpicture}
      \begin{axis}[
          scaled y ticks = false,
          y tick label style={/pgf/number format/fixed, /pgf/number format/fixed zerofill, /pgf/number format/precision=2},
        ]
    \addplot[color=black] coordinates {
        (1, 1)
        (2, 2)
        (3, 3)
        (4, 4)
        (5, 5)
        (6, 6)
        (7, 7)
        (8, 8)
      };
  \end{axis}

\end{tikzpicture}
\caption{}

\end{subfigure}%
  \[5mm]
  \begin{subfigure}{\linewidth}%
    \centering
    \begin{tikzpicture}
      \begin{axis}[
          scaled y ticks = false,
          y tick label style={/pgf/number format/fixed, /pgf/number format/fixed zerofill, /pgf/number format/precision=2},
        ]
    \addplot[color=black] coordinates {
        (-100, -1)
        (200, 2)
        (300, 3)
      };
  \end{axis}

\end{tikzpicture}
\caption{}

\end{subfigure}  %
  \caption{asd}
\end{figure}
\end{document}

@dexteritas I made the change and it worked. But I then made some changes to the input-data, and then it stopped working (see the updated OP) - can you spot why? — TylerD, Oct 18 '23 at 13:39
See my first comment here https://tex.stackexchange.com/questions/691966/align-tikzpicture-plots-subfigures-horizontally-and-vertically about the causes, and a fine solution by another member of this community. — MS-SPO, Oct 18 '23 at 20:44

score 1 · Answer 1 · answered Oct 19 '23 at 17:38

You must expand the width assigned to the y-labels (in both plots) to accommodate the minus sign.

\documentclass[12pt, a4paper]{article}
\usepackage[english]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{graphicx}
\usepackage{multirow}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{array}
\usepackage{subcaption}
\usepackage[hmargin=1in, vmargin=1.2in]{geometry}
\usepackage[labelfont=bf]{caption}
\captionsetup{width=.98\linewidth}
\usepackage{setspace}
\setstretch{1.3}
\usepackage{pgfplots}
\usepackage{tikz}
\pgfplotsset{compat=1.18}
\begin{document}
\begin{figure}[h]
    \pgfplotsset{yticklabel style = {text width=2.5em, align=right}}% added &lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;        

    \begin{subfigure}{\linewidth}
    \centering
    \begin{tikzpicture}
        \begin{axis}[
            scaled y ticks = false,
            y tick label style={/pgf/number format/fixed, /pgf/number format/fixed zerofill, /pgf/number format/precision=2},
            ]

            \addplot[color=black] coordinates {
                (1, 1)
                (2, 2)
                (3, 3)
                (4, 4)
                (5, 5)
                (6, 6)
                (7, 7)
                (8, 8)
            };
        \end{axis}

    \end{tikzpicture}
    \caption{}
\end{subfigure}%
\\[5mm]
\begin{subfigure}{\linewidth}%
    \centering
    \begin{tikzpicture}
        \begin{axis}[
            scaled y ticks = false,
            y tick label style={/pgf/number format/fixed, /pgf/number format/fixed zerofill, /pgf/number format/precision=2},
            ]

            \addplot[color=black] coordinates {
                (-100, -1)
                (200, 2)
                (300, 3)
            };
        \end{axis}

    \end{tikzpicture}
    \caption{}
\end{subfigure}  %
\caption{asd}

\end{figure}
\end{document}

score 0 · Answer 2 · answered Oct 18 '23 at 14:22

This is happening because you are using \centering and your plots are not precisely the same width: the minus sign in the bottom figure makes it just slightly wider. It is almost but not quite perfectly lined up if I put \phantom{+} right before the first tikzpicture environment, and you could replace that or augment it with \hspace commands to get it to line up perfectly by hand.

TikZ-subfigures are not horizontally aligned

2 Answers2