How to define variables with white space

Question

I'm writing a LaTex document in which I must refer to some variables in some points of the document. In order to ensure that each variable is written in the same way, I defined a LaTex variable for each of them.

\documentclass[border=10pt]{standalone}
\usepackage{algorithm,algpseudocode}

\newcommand{\varu}{\emph{u}}
\newcommand{\varv}{\emph{v}}
\newcommand{\varz}{\emph{z}}
\newcommand{\varTr}{\emph{Training}}
\newcommand{\varRzT}{$R_{\varz_{\varTr}$ } }
\newcommand{\varReaz}{$R_{EAz}$ }
\newcommand{\varRecScore}{$s(\varv, \vart | \varu)$ }
\newcommand{\varCS}{Cand Set}
\newcommand{\varw}{\emph{w}(\varu,\varv)}
\newcommand{\varBC}{$\mathrm{BC}_{suff}$}

\begin{document}
My text is quite long. In the text there can 
be referred some variables like \varu
which I would like is written as emph and after
the variable there is a white space.

Some of these variables are also inserted into 
an algorithm structure defined with algorithm.

\end{document}

I use these variables in some points of the document: in the text, in math mode and into an algorithm structure. My problem is that if I use these variables in the text, there is no white space after them. (i.e. after variable \varu there is no space).

How can I resolve it? I can't define \varu with the white space \newcommand{\varu}{\emph{u }} because when if the variable is followed by "." the white space is not correct.

Answer 1

Your approach is wrong under many respects.

1. You should use math italic, not \emph, except for multiletter variables; on the other hand “Training” is text, so it should be upright.

2. Math formulas should be in math mode, even if it's just one variable.

\newcommand{\varu}{u}
\newcommand{\varv}{v}
\newcommand{\varz}{z}
\newcommand{\varTr}{\mathrm{Training}}
\newcommand{\varRzT}{R_{\varz_{\varTr}}}
\newcommand{\varReaz}{R_{EAz}}
\newcommand{\varRecScore}{s(\varv,\vart\mid\varu)}
\newcommand{\varCS}{\mathrm{Cand\ Set}}
\newcommand{\varw}{w(\varu,\varv)}
\newcommand{\varBC}{\mathrm{BC}_{\mathrm{suff}}}

Then your text might be, more simply,

My text is quite long. In the text there can 
be referred some variables like $\varu$
and after the variable there is a white space.
\begin{equation}
(\varu,\varv) = \varu * \varv - \varRzT
\end{equation}

Answer 2

\usepackage{xspace}
\newcommand\varu{$u$\xspace}

Answer 3

LaTeX ignores the white spaces after commands. To ensure you get a space when you want it, use \varu\ . i.e. add a backslash before the space.