Problem with \newcommand and \renewcommand

boldmacrosmath-moderenewcommand

I am trying to define a command called \vec{} that prints a bold and non-italic symbol in math environment.

\renewcommand{\vec}[1]{\mathbf{#1}}

usually works for me, but not in the documentclass ifacconf.
Instead,

\newcommand{\vect}[1]{\mathbf{#1}}

works here. Can someone please explain the difference to me?

Thank you! 🙂

MWE:

\documentclass{ifacconf}
\usepackage{natbib}        % required for bibliography
%% own packages
\usepackage{amsmath}
\usepackage{amssymb}

%% own commands
\renewcommand{\vec}[1]{\mathbf{#1}}
\newcommand{\vect}[1]{\mathbf{#1}}

\begin{document}
\begin{frontmatter}

\title{Title, preferably not more than 10 words}

\begin{abstract}                
Abstract of not more than 250 words.
\end{abstract}

\end{frontmatter}
\begin{verbatim}
\mathbf{A}
\end{verbatim} prints
\begin{equation}
\mathbf{A},
\end{equation}

\begin{verbatim}
\vec{A}
\end{verbatim} prints
\begin{equation}
\vec{A},
\end{equation}

\begin{verbatim}
\vect{A}
\end{verbatim} prints
\begin{equation}
\vect{A}
\end{equation}
\end{document}

Best Answer

I think the problem is simple: frontmatter overwrites your command. Solution: Just copy your line

\renewcommand{\vec}[1]{\mathbf{#1}}

and paste it after you ended frontmatter or even inside the frontmatter environment to get your command inside this environment there.

I hope this helps!

Cheers, Nick

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[Tex/LaTex] Problem with \renewcommand

Your code doesn't work because you are using the same command as new and as old command in

\renewcommand{\footnotesize}{\footnotesize}

The right way to do it, is to first save the meaning of \footnotesize

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and when you want to restore its meaning, use

\renewcommand{\footnotesize}{\oldfootnotesize}

So, modifying your MWE to

\documentclass{article}
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Here is some text. And Here is some text with a footnote.\footnote{Here is the footnote text.}

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Notes:  The top panel plots the average leave probability for one-year age bins for the 2002 sample, while the bottom panel separately plots these probabilities for the 2002 and 1999-2001 samples.
}
\end{figure}

\end{document}

works.

[Tex/LaTex] Problem with \newcommand and \text

You need amsmath to be loaded in order to use \text. And the default setting for LyX is to "load [it] automatically". However, this automated loading requires you to use some amsmath-related environment (see Insert > AMS *), and unfortunately defining \text in a \newcommand doesn't invoke this loading.

You can change this choice so that amsmath is "load[ed] always" via Document > Settings... > Math Options > amsmath > "load always":

Note that LaTeX, like most programming languages, provides some form of scope to its definitions. So, if you Insert > TeX Code somewhere inside a table (just as an example) with the code being \newcommand{\kon}{k_\text{on}}, that macro - \kon - will only have a limited scope within the table environment. That's why it is usually best to insert definitions inside the Document > Settings... > LaTeX Preamble. Alternatively, you can always create your own definitions in a separate .style or .inc file that you include.

Best Answer

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[Tex/LaTex] Problem with \renewcommand

[Tex/LaTex] Problem with \newcommand and \text

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