[Tex/LaTex] Integer arithmetic in TeX

counters

After many years of being merely a regular TeX (LaTeX lately) I started reading little bit more recently. I wrote a small program (very naive) which is suppose to illustrate doing integer arithmetic in TeX.

\message{Please enter the first number:}
\read-1 to \first

The first entered number is \first

\count0=\first

\message{Please enter the second number:}
\read-1 to \second

\count1=\second

The second entered number is \second

\advance\count0 by \count1


Could you please compare the sum of number you have entered and
the number of the page :)
\bye

Is there a simple way to recover the content of register \count0 on an arbitrary place on the page?

Best Answer

In order to obtain \count0, use \the\count0. This will typeset the value of \count0 wherever it is used.

enter image description here

\message{Please enter the first number:}
\read-1 to \first

The first entered number is \first

\count0=\first

\message{Please enter the second number:}
\read-1 to \second

\count1=\second

The second entered number is \second

\advance\count0 by \count1


Could you please compare the sum of number you have entered and
the number of the page :) \the\count0
\bye

Related Solutions

[Tex/LaTex] “Arithmetic overflow” error

Using bigintcalc (from the oberdiek bundle), you can obtain the following output:

enter image description here

\documentclass{article}
\usepackage{bigintcalc}% http://ctan.org/pkg/bigintcalc
\begin{document} 
\newcount\n \newcount\p \newcount\m
\def\factorial#1{%
  {\m=#1\advance\m by 1
   \n=1
   \p=1
   \loop\ifnum\n<\m \multiply\p by \n \advance\n by 1 \repeat\number\p}}
\def\printfactorials#1{%
  \m=#1\advance\m by 1
  \n=0
  \loop\ifnum\n<\m \hfil\break\number\n! = \factorial{\n} \advance\n by 1 \repeat}

\def\bigfactorial#1{%
  \bigintcalcFac{#1}%
}
\def\printbigfactorials#1{%
  \m=#1\advance\m by 1
  \n=0
  \loop\ifnum\n<\m \hfil\break\number\n! = \bigfactorial{\the\n} \advance\n by 1 \repeat}

%\printfactorials{12}
\printbigfactorials{20}
\end{document}

\bigintcalcXXX is the basic operators that are defined. \bigintcalcFac{<x>} returns the factorial of <x>. According to the bigintcalc documentation,

Package bigintcalc defines arithmetic operations that deal with big integers. Big integers can be given either as explicit integer number or as macro code that expands to an explicit number. Big means that there is no limit on the size of the number. Big integers may exceed TeX's range limitation of -2147483647 and 2147483647. Only memory issues will limit the usable range.

[Tex/LaTex] How to perform simple arithmetic with page number

There are a few options.

If you want to globally change the page number, you can use \addtocounter or \setcounter, as recommended by Thorsten Donig.

If you want to use the result in a length or counter, as in \setcounter, \addtocounter, \setlength, or \addtolength, you can use the calc package. For example, one less than the page number is \setcounter{pagelessone}{\thepage-1}, where pagelessone is some counter you've already defined.

If you want to do something more complicated, you can use the eTeX primitives \dimexpr and \numexpr. For example, one less than the page number is \numexpr\thepage-1\relax. For more information, see section 3.5 of the eTeX documentation.

Best Answer

Related Solutions

[Tex/LaTex] “Arithmetic overflow” error

[Tex/LaTex] How to perform simple arithmetic with page number

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