Label position in equation environment

Question

I am looking for a way to align the label of an equation environment to the base line of the formula text. The default behavior of

\begin{equation}
\begin{array}{llr} 
\hat x &= \underset{x} {\text{arg\,min}} & f(x)+ \sum_i \lambda_i g_i(x)
\end{array} \tag{SomeLabel}
\end{equation}

seems to produce

Here, the label is actually vertically centered to the whole equation. I think it would be nicer if it was aligned with the base line. Anyone know how to fix this?

Unfortunately "you're doing it wrong." There's no need for an array here. — Werner, Dec 23 '19 at 17:36
If you must use array, move the label down one line, just before the \end{equation}. — barbara beeton, Dec 23 '19 at 20:58

score 4 · Accepted Answer · answered Dec 23 '19 at 17:34

4

Why array?

\documentclass{article}
\usepackage{amsmath}

\DeclareMathOperator*{\argmin}{arg\,min}

\begin{document}

\begin{equation}
\hat x = \argmin_{x} f(x)+ \sum_i \lambda_i g_i(x)
\tag{SomeLabel}
\end{equation}

\end{document}

answered Dec 23 '19 at 17:34

egreg

1,121,712

You are absolutely right. I used 'array' because sometimes there are additional constraints to the optimization problem, so multiple lines. But, here it is not needed. Thanks. – Sirg Dec 30 '19 at 14:50

Label position in equation environment

1 Answers1