Align equations separated by paragraphs

Question

I would like to align equations separated by paragraphs while retaining there auto-generated label and \listof label for after the toc. How would I align these equations and keep the \listofmyequations and \label intact?

\documentclass[11pt,a4paper,twoside,openright,fleqn,%
headinclude,footinclude,parskip=half,%
numbers=noenddot,cleardoublepage=empty]{scrbook}
\usepackage[utf8]{inputenc}
\usepackage[notlof,notlot,notbib]{tocbibind} 
\usepackage{tocloft}
\usepackage{amsmath,amssymb,amsthm}
%\usepackage[ruled,vlined,algochapter,linesnumbered]{algorithm2e}
\usepackage{pdfpages}
%-- colours for the hyperlinks
%\usepackage[usenames,dvipsnames]{xcolor}
\definecolor{colorforlinks}{RGB}{27, 60, 131}
\usepackage[breaklinks=true,
    colorlinks=true,
    linktocpage=true,
    allcolors=colorforlinks]{hyperref} 

\newcommand{\listequationsname}{List of Equations}

\newlistof{myequations}{equ}{\listequationsname}
\newcommand{\myequations}[1]{%
    \addcontentsline{equ}{myequations}{\protect\numberline{\theequation}#1}\par}

\begin{document}

\listofmyequations

\chapter{Precision and Accuracy}

The precision, or repeatability, and a paragraph of words here: 

\begin{equation}
    \label{eq:std}
    \sigma = \sqrt{\frac{\sum_{i=1}^{n}(x_{i,j} - \bar{x})^{2}}{n-1}}    
\end{equation}
\myequations{Standard Deviation}
where \(i\) is the epoch number, \(j\) is the \(x\),\(y\) and \(z\) component, \(x_{i,j}\) is the measurement at the epoch of observation, \(\bar{x}\) is the mean of \(j\) measurements and \(n\) is the total number of epochs. 

Then some words about Accuracy for a paragraph or so:
\begin{equation}
    \label{eq:rms}
    RMS_{x,\,y \,or\, z} = \sqrt{\frac{\sum_{i=1}^{n}(P_{i}-O)^{2}}{n}}
\end{equation}
\myequations{Root Mean Square}

Furthermore; some words about 2-dimensional RMS or 2DRMS:
\begin{equation}
    \label{eq:2drms}
    2DRMS = 2 * \sqrt{ RMS_{x}^{2} + RMS_{y}^{2}} 
\end{equation}
\myequations{Distance Root Mean Square}

where \(RMS_{x}\) and \(RMS_{y}\) are the RMS for the \(x\) and \(y\)  components respectively.

Lastly; a paragraph or so about Mean Radial Spherical Error:
\begin{equation}
    \label{eq:mrse}
    MRSE = \sqrt{ RMS_{x}^{2} + RMS_{y}^{2} + RMS_{u}^{2}} 
\end{equation}
\myequations{Mean Radial Spherical Error}

where \(RMS_{x}\), \(RMS_{y}\) and \(RMS_{z}\) are the RMS for the \(x\), \(y\) and \(z\) components respectively.

\end{document}

I have tried \intertext and \shortintertext but failed. Perhaps I am placing these incorrectly. I don't know.

Answer 1

In your MWE replace

\usepackage{amsmath,amssymb,amsthm}

with

\usepackage[fleqn,reqno]{amsmath}
\setlength{\mathindent}{3pc} % or another length to suit you
\usepackage{amssymb,amsthm}

Answer 2

The solution was to remove the equation and go with align and \intertext{ with \myequations{name of the equation} inside the intertext}.

This might be a bit long-winded but keeps the \listofmyequations intact and references the auto-generated \label correctly.

\documentclass[11pt,a4paper,twoside,openright,fleqn,%
headinclude,footinclude,parskip=half,%
numbers=noenddot,cleardoublepage=empty]{scrbook}
\usepackage[utf8]{inputenc}
\usepackage[left=15mm,top=10mm]{geometry}
\usepackage[notlof,notlot,notbib]{tocbibind} 
\usepackage{tocloft}
\usepackage{amsmath,amssymb,amsthm}
\usepackage{pdfpages}

%-- colours for the hyperlinks
\definecolor{colorforlinks}{RGB}{27, 60, 131}
\usepackage[breaklinks=true,
colorlinks=true,
linktocpage=true,
allcolors=colorforlinks]{hyperref} 
\setlength{\parindent}{2pc}

\newcommand{\listequationsname}{List of Equations}

\newlistof{myequations}{equ}{\listequationsname}
\newcommand{\myequations}[1]{%
    \addcontentsline{equ}{myequations}{\protect\numberline{\theequation}#1}\par}

\begin{document}
    
    \listofmyequations
    
    \chapter{Precision and Accuracy}
    
    The precision, or repeatability, and a paragraph of words here: 
    
    \begin{align}
        STD &= \sqrt{\frac{\sum_{i=1}^{n}(x_{i,j} - \bar{x})^{2}}{n-1}}    \label{eq:std} 
        \intertext{\myequations{Standard Deviation} \noindent where \(i\) is the epoch number, \(j\) is the \(x\),\(y\) and \(z\) component, \(x_{i,j}\) is the measurement at the epoch of observation, \(\bar{x}\) is the mean of \(j\) measurements and \(n\) is the total number of epochs.}
        \intertext{\indent Then some words about Accuracy for a paragraph or so:}
        RMS_{x,\,y \,or\, z} &= \sqrt{\frac{\sum_{i=1}^{n}(P_{i}-O)^{2}}{n}}  \label{eq:rms} 
        \intertext{ \myequations{Root Mean Square}  \noindent where \(x\),\(y\) and \(z\) are the horizontal and vertical coordinate components, \(P\) is the measured Real-Time ppp value, \(O\) the \emph{true} reference value, \(i\) is the epoch of observation and \(n\) is the total number of epochs.} 
        \intertext{\indent Furthermore; some words about 2-dimensional RMS or 2DRMS:}
        2DRMS &= 2 * \sqrt{ RMS_{x}^{2} + RMS_{y}^{2}} \label{eq:2drms}
        \intertext{\myequations{Distance Root Mean Square}  \noindent where \(RMS_{x}\) and \(RMS_{y}\) are the RMS for the \(x\) and \(y\)  components respectively.}
        \intertext{\indent Lastly; a paragraph or so about Mean Radial Spherical Error:}
        MRSE &= \sqrt{ RMS_{x}^{2} + RMS_{y}^{2} + RMS_{u}^{2}} \label{eq:mrse}
    \end{align}
    \myequations{Mean Radial Spherical Error}
    \noindent where \(RMS_{x}\), \(RMS_{y}\) and \(RMS_{z}\) are the RMS for the \(x\), \(y\) and \(z\) components respectively.
\end{document}

Answer 3

A small variation of OP answer (+1), which result (to my opinion) in better looking page. You may find the following suggestions useful:

• redefined is \myequations
• successive `intertext are merged in one
• defined is new command for simulating paragraphs in \intertext

\documentclass[11pt,a4paper,twoside,openright,fleqn,%
                headinclude,footinclude,parskip=half,%
                numbers=noenddot,cleardoublepage=empty]{scrbook}
\usepackage{geometry}
\usepackage[notlof,notlot,notbib]{tocbibind}
\usepackage{tocloft}
\usepackage{amsmath,amssymb,amsthm}

\usepackage{lipsum}

\usepackage{pdfpages}
\definecolor{colorforlinks}{RGB}{27, 60, 131}
\usepackage[breaklinks=true,
            colorlinks=true,
            linktocpage=true,
            allcolors=colorforlinks]{hyperref}
            
\newcommand{\listequationsname}{List of Equations}
\newlistof{myequations}{equ}{\listequationsname}
\newcommand{\myequations}[1]{%
    \addcontentsline{equ}{myequations}{\protect\numberline{\theequation}#1}\ignorespaces}
\newcommand\inl{
\setlength{\parindent}{2pc}

\begin{document}
\listofmyequations

\chapter{Precision and Accuracy}
The precision, or repeatability, and a paragraph of words here:
    \begin{align}
        STD &= \sqrt{\frac{\sum_{i=1}^{n}(x_{i,j} - \bar{x})^{2}}{n-1}}     \label{eq:std}
\intertext{\myequations{Standard Deviation} 
    where \(i\) is the epoch number, \(j\) is the \(x\),\(y\) and \(z\) component, \(x_{i,j}\) is the measurement at the epoch of observation, \(\bar{x}\) is the mean of \(j\) measurements and \(n\) is the total number of epochs. 
    \newline\indent
Then some words about Accuracy for a paragraph or so:}
        \mathrm{RMS}_{x,\,y \,\mathrm{or}\, z} 
            & = \sqrt{\frac{\sum_{i=1}^{n}(P_{i}-O)^{2}}{n}}                \label{eq:rms}
\intertext{\myequations{Root Mean Square}  
    where \(x\),\(y\) and \(z\) are the horizontal and vertical coordinate components, \(P\) is the measured Real-Time ppp value, \(O\) the \emph{true} reference value, \(i\) is the epoch of observation and \(n\) is the total number of epochs. 
    \newline\indent
    Furthermore; some words about 2-dimensional RMS or 2DRMS:}
        2\mathrm{DRMS} 
            & = 2 * \sqrt{ RMS_{x}^{2} + RMS_{y}^{2}}                       \label{eq:2drms}
\intertext{\myequations{Distance Root Mean Square}  
    \noindent where \(RMS_{x}\) and \(RMS_{y}\) are the RMS for the \(x\) and \(y\)  components respectively. 
    \newline\indent
    Lastly; a paragraph or so about Mean Radial Spherical Error:}
        \mathrm{MRSE} 
            & = \sqrt{ RMS_{x}^{2} + RMS_{y}^{2} + RMS_{u}^{2}}             \label{eq:mrse}
    \end{align}\myequations{Mean Radial Spherical Error}
where \(\mathrm{RMS}_{i},\; i\in\{x,y,z\}\) are the RMS for the \(x\), \(y\) and \(z\) components respectively.

\lipsum[66]
\end{document}

Edit: However, it is not clear, why is needed such complicated structure of this equation. That equation on this page are aligned at =?

Well, this is mater of personal taste. I do not see any advantages. More usual way of writing text at least is much simpler and consequently less error prone:

\documentclass[11pt,a4paper,twoside,openright,fleqn,%
                headinclude,footinclude,parskip=half,%
                numbers=noenddot,cleardoublepage=empty]{scrbook}
\usepackage{geometry}
\usepackage[notlof,notlot,notbib]{tocbibind}
\usepackage{tocloft}
\usepackage{amsmath,amssymb,amsthm}

\usepackage{lipsum}

\usepackage{pdfpages}
\definecolor{colorforlinks}{RGB}{27, 60, 131}
\usepackage[breaklinks=true,
            colorlinks=true,
            linktocpage=true,
            allcolors=colorforlinks]{hyperref}

\newcommand{\listequationsname}{List of Equations}
\newlistof{myequations}{equ}{\listequationsname}
\newcommand{\myequations}[1]{%
    \addcontentsline{equ}{myequations}{\protect\numberline{\theequation}#1}\ignorespaces}
\setlength{\parindent}{2pc}

\begin{document}
\listofmyequations

\chapter{Precision and Accuracy}
The precision, or repeatability, and a paragraph of words here:
    \begin{equation}\label{eq:std}
STD = \sqrt{\frac{\sum_{i=1}^{n}(x_{i,j} - \bar{x})^{2}}{n-1}}                  
    \end{equation}\myequations{Standard Deviation}
where \(i\) is the epoch number, \(j\) is the \(x\),\(y\) and \(z\) component, \(x_{i,j}\) is the measurement at the epoch of observation, \(\bar{x}\) is the mean of \(j\) measurements and \(n\) is the total number of epochs.

Then some words about Accuracy for a paragraph or so:
    \begin{equation}\label{eq:rms}
\mathrm{RMS}_{x,\,y \,\mathrm{or}\, z} = \sqrt{\frac{\sum_{i=1}^{n}(P_{i}-O)^{2}}{n}}    
    \end{equation}\myequations{Root Mean Square}
where \(x\),\(y\) and \(z\) are the horizontal and vertical coordinate components, \(P\) is the measured Real-Time ppp value, \(O\) the \emph{true} reference value, \(i\) is the epoch of observation and \(n\) is the total number of epochs.

Furthermore; some words about 2-dimensional RMS or 2DRMS:
    \begin{equation}\label{eq:2drms}
2\mathrm{DRMS}= 2 * \sqrt{ RMS_{x}^{2} + RMS_{y}^{2}}                           
    \end{equation}\myequations{Distance Root Mean Square}
where \(RMS_{x}\) and \(RMS_{y}\) are the RMS for the \(x\) and \(y\)  components respectively.

Lastly; a paragraph or so about Mean Radial Spherical Error:
    \begin{equation}\label{eq:mrse}
\mathrm{MRSE} = \sqrt{ RMS_{x}^{2} + RMS_{y}^{2} + RMS_{u}^{2}}             
    \end{equation}\myequations{Mean Radial Spherical Error}
where \(\mathrm{RMS}_{i},\; i\in\{x,y,z\}\) are the RMS for the \(x\), \(y\) and \(z\) components respectively.

\lipsum[66]
\end{document}