# alignment inside split and align

I would like to have (Kollo Skewness) to be aligned on the right with (Row Sums) and (Orthogonality) while keeping (4.16) in between the third and fourth line.

This is my code

\begin{align}
&\mathbf{L}_{mn}'\mathbf{L}_{mn}  = m \mathbf{I}_n & \text{(Orthogonality)}\\
&\mathbf{1}_m^{'} \mathbf{L}_{mn}  = \mathbf{0}'_n & \text{(Row Sums)} \\
\begin{split} \label{eq:kollo:b}
&\mathbf{b} = m^{-1} \left[ s_1 \mathbf{c}_1 + \dots + s_m \mathbf{c}_m  \right]  \text{(Kollo skewness)}\\
&\text{where} \quad s_k = \left(c_{1k} + \dots + c_{nk}  \right)^2 = \left( \mathbf{1}' \mathbf{c}_k \right)^2
\end{split}
\end{align}


This might have also been answered elsewhere. If so please point me there. I was unable to find it.

This is a minimum example

\documentclass[12pt,a4paper]{report}
\usepackage{amsmath,amsfonts,amsthm}
\setlength{\topmargin}{1.5cm}
\setlength{\topskip}{12pt}
\setlength{\evensidemargin}{0pt}
\setlength{\oddsidemargin}{0pt}
\setlength{\textheight}{240mm}
\setlength{\textwidth}{160mm}
\setlength{\voffset}{-2cm}
\setlength{\parindent}{0pt}
\setlength{\parskip}{6pt}

\begin{document}
\begin{align}
&\mathbf{L}_{mn}'\mathbf{L}_{mn}  = m \mathbf{I}_n & \text{(Orthogonality)}\\
&\mathbf{1}_m^{'} \mathbf{L}_{mn}  = \mathbf{0}'_n & \text{(Row Sums)} \\
\begin{split} \label{eq:kollo:b}
&\mathbf{b} = m^{-1} \left[ s_1 \mathbf{c}_1 + \dots + s_m \mathbf{c}_m  \right]  \text{(Kollo skewness)}\\
&\text{where} \quad s_k = \left(c_{1k} + \dots + c_{nk}  \right)^2 = \left( \mathbf{1}' \mathbf{c}_k \right)^2
\end{split}
\end{align}
\end{document}

• Welcome to TeX.SX! Please make your code compilable (if possible), or at least complete it with \documentclass{...}, the required \usepackage's, \begin{document}, and \end{document}. That may seem tedious to you, but think of the extra work it represents for TeX.SX users willing to give you a hand. Help them help you: remove that one hurdle between you and a solution to your problem. – dexteritas Sep 19 '17 at 9:02
• It seems there is missing a & before \text{(Kollo skewness)}. – dexteritas Sep 19 '17 at 9:04
• adding the extra & gives me the following error Extra alignment tab has been changed to \cr. [ \end{align}] – PalimPalim Sep 19 '17 at 9:21
• also minimum compilable example has been added. – PalimPalim Sep 19 '17 at 9:21

Here are two different possible alignments, with aligned instead of split:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{mathtools}
\usepackage{cleveref}

\begin{document}

\begin{align}
&\mathbf{L}_{mn}'\mathbf{L}_{mn} = m \mathbf{I}_n & \text{(Orthogonality)}\\
&\mathbf{1}_m^{'} \mathbf{L}_{mn} = \mathbf{0}'_n & \text{(Row Sums)} \\
& \begin{aligned}[t] \label{eq:kollo:b}
&\mathbf{b} = m^{-1} \left[ s_1 \mathbf{c}_1 + \dots + s_m \mathbf{c}_m \right]\\
&\quad\text{where} \quad s_k = \left(c_{1k} + \dots + c_{nk} \right)^2 = \left( \mathbf{1}' \mathbf{c}_k \right)^2
\end{aligned} & \text{(Kollo skewness)}
\end{align}

\Cref{eq:kollo:b}

\begin{align}
&\mathbf{L}_{mn}'\mathbf{L}_{mn} = m \mathbf{I}_n & & \text{(Orthogonality)}\\
&\mathbf{1}_m^{'} \mathbf{L}_{mn} = \mathbf{0}'_n & & \text{(Row Sums)} \\
& \begin{aligned}[t] \label{eq:kollo:c}
&\mathbf{b} = m^{-1} \left[ s_1 \mathbf{c}_1 + \dots + s_m \mathbf{c}_m \right]\\
&\quad\text{where} \quad s_k = \left(c_{1k} + \dots + c_{nk} \right)^2 = \left( \mathbf{1}' \mathbf{c}_k \right)^2
\end{aligned} & & \text{(Kollo skewness)}
\end{align}

\end{document}


• Thanks @Bernard. I would prefer if the (3) and (6) would be in between lines 3 & 4 and not on the third line. Is this possible? – PalimPalim Sep 19 '17 at 9:19
• solved it with the help of your answer. Thanks a lot! – PalimPalim Sep 19 '17 at 9:31
• Yes, it is: remove the optional [t] of aligned, or use split. From my point of view, it made more sense to have the equation number aligned on the first line, because the second line is just an add-on, but that's a matter of personal choice. – Bernard Sep 19 '17 at 9:33
• Can you have (Kollo skewness) on the same line als the third equation and the number (3) in between the third and fourth equation? I'm not sure if that is what OP wanted, but it would be interesting to know. – jaytar Sep 19 '17 at 9:40

From Bernard's answer I saw how he put the & outside of the nested aligned the same worked for me with split. This way my second requirement, having the numbering between lines 3 & 4 is still fullfilled.

\begin{align}
&\mathbf{L}_{mn}'\mathbf{L}_{mn}  = m \mathbf{I}_n & \text{(Orthogonoalitly)}\\
&\mathbf{1}_m^{'} \mathbf{L}_{mn}  = \mathbf{0}'_n & \text{(Row Sums)} \\
\begin{split} \label{eq:kollo:b}
&\mathbf{b} = m^{-1} \left[ s_1 \mathbf{c}_1 + \dots + s_m \mathbf{c}_m  \right]  \\
&\quad \text{where} \quad s_k = \left(c_{1k} + \dots + c_{nk}  \right)^2 = \left( \mathbf{1}' \mathbf{c}_k \right)^2
\end{split} & \text{(Kollo skewness)}
\end{align}


• Just a small comment: I think you should add a \quad before where in the last line. Semantically, this last line doesn't have the same status as the others. – Bernard Sep 19 '17 at 9:41