Vertical Space between formula and brackets

Question

I have the following; however I want to add more space between the formula and the underbrackets so that it doesn't look so squished. How can I do that?

\documentclass[a4paper]{article}   
\usepackage{mathtools}
\begin{document}
   \begin{equation}\label{eq:reprojection_error_final}
        f=\min_{\hat{P}^i, \hat{X}_j}
        \sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{d(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{d(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{d(\hat{X}_0, 0)}_{\text{Ursprungsdiff.}}\Bigr]^2
        \end{equation}
\end{document}

Current result:

Can you provide a Minimal Working Example? What are the packages that you use? — Sina Ahmadi, Nov 09 '18 at 13:54
@SinaAhmadi I edited the question; I'm using the mathtools package. — John, Nov 09 '18 at 14:10
MathToolspackage documentation does not mention anything regarding that distance. This is the only thing provided: \underbracket[〈rule thickness〉] [〈bracket height〉]{〈arg〉}and \overbracket[〈rule thickness〉] [〈bracket height〉]{〈arg〉}. — Sina Ahmadi, Nov 09 '18 at 14:12
Yes I know; but I thought somebody here might know a trick to get the spacing anyway — John, Nov 09 '18 at 14:19
I can suggest using Tikz to manually add the brackets wherever you would like. It'll be a little bit messy but will do what you're looking for. — Sina Ahmadi, Nov 09 '18 at 14:24

Bernard · Accepted Answer · 2018-11-09T16:47:51.677

You can use the bigstrut package: \bigstrut[b] adds avertical distance below the insertion point, and this distance is controlled by the value of \bigstrutjot:

\documentclass[a4paper]{article}
\usepackage{mathtools}
\usepackage{bigstrut}

\begin{document}

\begin{equation}\label{eq:reprojection_error_final}
    f=\min_{\hat{P}^i, \hat{X}_j}
    \sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{X}_0, 0)}_{\text{\clap{Ursprungsdiff.}}}\Bigr]^2
\end{equation}

\begin{equation}\label{eq:reprojection_error_final}
\setlength{\bigstrutjot}{1.5ex}
    f=\min_{\hat{P}^i, \hat{X}_j}
    \sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{\bigstrut[b]d(\hat{X}_0, 0)}_{\text{\clap{Ursprungsdiff.}}}\Bigr]^2
\end{equation}

\end{document}

score 4 · Answer 2 · answered Nov 09 '18 at 14:20

Also check out \vphantom

\documentclass[a4paper]{article}   
\usepackage{mathtools}
\begin{document}
   \begin{equation}\label{eq:reprojection_error_final}
        f=\min_{\hat{P}^i, \hat{X}_j}
        \sum_{ij} \Bigl[\underbracket[1.5pt][8pt]{d_{\strut}(\hat{P}^i \hat{X}_j, x^i_j)}_{\text{Projektionsdiff.}} + \underbracket[1.5pt][8pt]{d_{\strut}(L_k^m - L_{k+1}^m ,\hat{X}_k^m - \hat{X}_{k+1}^m)}_{\text{3D-Punkt-Differenz}} + \underbracket[1.5pt][8pt]{d_{\strut}(\hat{X}_0, 0)}_{\text{Ursprungsdiff.}}\Bigr]^2
        \end{equation}
\end{document}

Vertical Space between formula and brackets

2 Answers2

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