[Tex/LaTex] Multiply the value by decimal number in latex

calculations

I used the following construct quite often:

\includegraphics[width=\textwidth/2]{pic.png}

But when I try to adjust the size a small bit, like this:

\includegraphics[width=\textwidth*0.45]{pic.png}

I get

! Package calc Error: `.' invalid at this point.

What am I doing wrong?

Best Answer

The calc package allows only division by integers or by reals which are announced as \real: so

\includegraphics[width=\textwidth*\real{0.45}]{pic}

will do, but

\includegraphics[width=0.45\textwidth]{pic}

works as well, doesn't require calc and is faster.

Related Solutions

[Tex/LaTex] Having trouble dividing lengths with calc package

Ian's answer pointed me into the right direction: This is easily possible with the adjustbox package by Martin Scharrer. It basically gives you an \includegraphics-like interface to be used with any (boxable) material:

\documentclass{article}
\usepackage{adjustbox}

\begin{document}

  \adjustbox{width=400pt,height=800pt,keepaspectratio=true}{Hello, World}

\end{document}

[Tex/LaTex] How to define a macro that uses image width and height to define a variable for later use

Please always show a complete document that generates the problem. You show some code and you show an error message, but not the code that generates the error.

TeX is a macro expansion language you can almost always put any sequence of commands in a macro and they work the same way. Here, where no catcode/verbatim trickery is used it is certainly possible.

\def\first{\includegraphics{#2}}
\def\first{\includegraphics{#3}}
\setlength{\gapspace}{#1}

That middle line should presumably be defining \second.

\setlength{\effwidth}{\textwidth-\gapspace}

would normally be a synax error but as you say it works, presumably you have loaded calc package? (Again it is much easier if you show a complete document with all relevant packages)

The syntax for \newcommand that you show is incorrect

\newcommand{\calcoptimalheight}{3}[0.5cm]{

Is not a syntax error but 3 is the entire body of the definition, you want

\newcommand{\calcoptimalheight}[3][0.5cm]{%

You probably want to add % at the end of every line as well.

Best Answer

Related Solutions

[Tex/LaTex] Having trouble dividing lengths with calc package

[Tex/LaTex] How to define a macro that uses image width and height to define a variable for later use

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