Define variables holding a percentage

Question

I would like to define some variables in a tex document. For example, I write in .tex something similar as: Our tool succeeds to validate x samples out of all the y samples, thus its success ratio is z. Where z is defined as x/y, and x (resp. y) is instanced somewhere else by a number, eg., 30 (resp. 47). As a result, after the compilation the text turns out to be Our tool succeeds to validate 30 samples out of all the 47 samples, thus its success ratio is 63.8%.

The advantage of this, is that I just need to change the value of some variables, to change all the numbers in the text... The difficulty is that z holds a percentage number.

Does anyone know how to achieve this?

This appears to be a follow-up to this question (additional requirements: floating-point arithmetic and some modifications for the percent symbol). — Paul Gessler, May 06 '14 at 15:22
@PredragPunosevac I tried your \directlua{tex.print(string.format("%.2f",2*(1234.56+9786.45)))}, but the compilation raised one error Undefined control sequence... — SoftTimur, May 06 '14 at 15:48
@SoftTimur I asked if you needed non integer values last time, and you said no:-) — David Carlisle, May 06 '14 at 16:05
@PredragPunosevac classic tex can do it as well of course:-) — David Carlisle, May 06 '14 at 16:05
@DavidCarlisle I was assuming he will go for non integer values and want to do some computations with it which of course also can be done in TeX but with little bit work to implement floating point arithmetics. — Predrag Punosevac, May 06 '14 at 16:18
@SoftTimur \directlua is a luatex primitive so you would be restricted to lualatex in that case. — David Carlisle, May 06 '14 at 16:31

David Carlisle · Answer 1 · 2014-05-06T18:04:17.627

5

\documentclass{article}

\newcommand\x{30}
\newcommand\y{47}


\newcommand\mypercent[2]{%
\expandafter\myadddot\the\numexpr 10000*(#1)/(#2)\relax\relax\%}

\def\myadddot#1#2#3{%
\ifx\relax#3%
.#1%
\else
#1\expandafter\myadddot\fi
#2#3}

\begin{document}


Our tool succeeds to validate \x\ samples out of all the \y\ samples, thus its success ratio is 
\mypercent{\x}{\y}


\end{document}

or for 1dp

\newcommand\mypercent[2]{%
\expandafter\adddot\the\numexpr 1000*(#1)/(#2)\relax\relax\%}

\def\adddot#1#2{%
\ifx\relax#2%
.#1%
\else
#1\expandafter\adddot\fi
#2}

edited May 06 '14 at 18:04

answered May 06 '14 at 16:30

David Carlisle

757,742

\adddot is used by biblatex. – egreg May 06 '14 at 16:32
1

@egreg a no doubt true but unrelated observation:-) – David Carlisle May 06 '14 at 16:33
code fails in case of 0% validation or for example with 1/3000 success rate ;-) – May 06 '14 at 17:02
Actually i always need 1 decimal digit after . (eg., %63.8 instead of 63.83), could you show me how to change your code? – SoftTimur May 06 '14 at 17:07
@SoftTimur answer updated – David Carlisle May 06 '14 at 18:04

score 3 · Answer 2 · edited Jun 10 '20 at 12:32

Yo can also use pgf math engine:

enter image description here

Notes:

The optional first parameter can be used to control the number of decimal digits displayed -- defaults to 2 digits if not specified.

Code:

\documentclass{article}
\usepackage{tikz}
\newcommand\x{30}
\newcommand\y{47}
\newcommand{\MyPercent}[3][2]{%
    \pgfmathparse{100*#2/#3}%
    \pgfmathprintnumber[fixed,precision=#1]{\pgfmathresult}%%
}%
\begin{document}
Our tool succeeds to validate \x\ samples out of all the \y\ samples, thus its success ratio is 
\MyPercent{\x}{\y}, or with more digits \MyPercent[5]{\x}{\y}.
\end{document}

score 3 · Answer 3 · answered May 06 '14 at 18:06

The mandatory solution with expl3; the optional argument is the number of decimal digits (default 0); the result is rounded.

\documentclass{article}
\usepackage{xparse}

\ExplSyntaxOn
\DeclareExpandableDocumentCommand\mypercent{O{0}mm}
 {
  \fp_eval:n { round ( 100 * #2/#3 , #1 ) } \%
 }
\ExplSyntaxOff

\newcommand\x{30}
\newcommand\y{47}

\begin{document}

Our tool succeeds to validate \x\ samples out of all the \y\ samples, thus its
success ratio is
\mypercent{\x}{\y}.

Our competitor validated only 1 sample out of 31. Her success ratio is thus
\mypercent{1}{31}, or, more precisely \mypercent [3]{1}{31}.

\end{document}

enter image description here

score 1 · Accepted Answer · answered May 06 '14 at 17:29

\documentclass{article}
\usepackage{xintfrac}

\newcommand\x{30}
\newcommand\y{47}


\newcommand\mypercent[3][1]{\xintRound {#1}{\xintE{#2/#3}{2}}\%}

\begin{document}\thispagestyle{empty}

Our tool succeeds to validate \x\ samples out of all the \y\ samples, thus its
success ratio is  
\mypercent{\x}{\y}.

Our competitor validated only 1 sample out of 31. Her success ratio is thus
\mypercent{1}{31}, or, more precisely \mypercent [3]{1}{31}.

\end{document}

Define variables holding a percentage

4 Answers4

Notes:

Code: