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+% Since we cannot be sure that this file is available at any
+% system, we have copied the original in this file. These
+% macros are encapsulates and extended in supp-ran.tex.
+%
+% This module is slightly recoded to bring it more in tune
+% with \CONTEXT's scratch registers and protection mechanisms.
+
+% RANDOM.TEX v.1 (Donald Arseneau)
+% Generating "random" numbers in TeX.
+%
+% Random integers are generated in the range 1 to 2147483646 by the
+% macro \nextrandom.  The result is returned in the counter \randomi.
+% Do not change \randomi except, perhaps, to initialize it at some
+% random value.  If you do not initialize it, it will be initialized
+% using the time and date.  (This is a sparse initialization, giving
+% fewer than a million different starting values, but you should use
+% other sources of numbers if they are available--just remember that
+% most of the numbers available to TeX are not at all random.)
+%
+% The \nextrandom command is not very useful by itself, unless you
+% have exactly 2147483646 things to choose from.  Much more useful
+% is the \setrannum command which sets a given counter to a random
+% value within a specified range.  There are three parameters:
+% \setrannum {<counter>} {<minimum>} {<maximum>}.  For example, to
+% simulate a die-roll: \setrannum{\die}{1}{6} \ifcase\die... .
+%
+% If you need random numbers that are not integers, you will have to
+% use dimen registers and \setrandimen.  For example, to set a random
+% page width: \setrandimen \hsize{3in}{6.5in}.  The "\pointless" macro
+% will remove the "pt" that TeX gives so you can use the dimensions
+% as pure `real' numbers.  In that case, specify the range in pt units.
+% For example,
+%
+%   \setrandimen\answer{2.71828pt}{3.14159pt}
+%   The answer is \pointless\answer.
+%
+% The random number generator is the one by Lewis, Goodman, and Miller
+% (1969) and used as "ran0" in "Numerical Recipies" using Schrage's
+% method for avoiding overflows.  The multiplier is 16807 (7^5), the
+% added constant is 0, and the modulus is 2147483647 (2^{31}-1).  The
+% range of integers generated is 1 - 2147483646.  A smaller range would
+% reduce the complexity of the macros a bit, but not much--most of the
+% code deals with initialization and type-conversion.  On the other hand,
+% the large range may be wasted due to the sparse seed initialization.
+
+% original code
+%
+% \newcount\randomi % the random number seed (while executing)
+% \global\randomi\catcode`\@  % scratch variable during definitions
+% \catcode`\@=11
+%
+% \def\nextrandom{\begingroup
+%  \ifnum\randomi<\plusone % then initialize with time
+%     \global\randomi\time
+%     \global\multiply\randomi388 \global\advance\randomi\year
+%     \global\multiply\randomi31 \global\advance\randomi\day
+%     \global\multiply\randomi97 \global\advance\randomi\month
+%     \message{Randomizer initialized to \the\randomi.}%
+%     \nextrandom \nextrandom \nextrandom
+%  \fi
+%  \count@ii\randomi
+%  \divide\count@ii 127773 % modulus = multiplier * 127773 + 2836
+%  \count@\count@ii
+%  \multiply\count@ii 127773
+%  \global\advance\randomi-\count@ii % random mod 127773
+%  \global\multiply\randomi 16807
+%  \multiply\count@ 2836
+%  \global\advance\randomi-\count@
+%  \ifnum\randomi<\z@ \global\advance\randomi 2147483647\relax\fi
+%  \endgroup
+% }
+%
+% \countdef\count@ii=2 % use only in boxes!
+% \ifx\@tempcnta\undefined \csname newcount\endcsname \@tempcnta \fi
+% \ifx\@tempcntb\undefined \csname newcount\endcsname \@tempcntb \fi
+%
+% \def\setrannum#1#2#3{% count register, minimum, maximum
+%  \@tempcnta#3\advance\@tempcnta-#2\advance\@tempcnta\@ne
+%  \@tempcntb 2147483645 %  =  m - 2  =  2^{31} - 3
+%  \divide\@tempcntb\@tempcnta
+%  \getr@nval
+%  \advance\ranval#2\relax
+%  #1\ranval
+% }
+%
+% \def\setrandim#1#2#3{% dimen register, minimum length, maximum length
+%  \dimen@#2\dimen@ii#3\relax
+%  \setrannum\ranval\dimen@\dimen@ii
+%  #1\ranval sp\relax
+% }
+%
+% \def\getr@nval{% The values in \@tempcnta and \@tempcntb are parameters
+%  \nextrandom
+%  \ranval\randomi \advance\ranval\m@ne \divide\ranval\@tempcntb
+%  \ifnum\ranval<\@tempcnta\else \expandafter\getr@nval \fi
+% }
+%
+% %D The next macro is not needed in \CONTEXT, which provides
+% %D the \type {\withoutpt} macro.
+% %D
+% %D \starttyping
+% %D \def\pointless{\expandafter\PoinTless\the}
+% %D {\catcode`p=12 \catcode`t=12 \gdef\PoinTless#1pt{#1}}
+% %D \stoptyping
+%
+% \catcode`\@=\randomi
+% \global\randomi=0
+% \newcount\ranval
+
+% the recoded version, using \CONTEXT\ methods and variables;
+% the magic is kept untouched
+
+\unprotect
+
+\newcount\randomi % the random number seed (while executing)
+\newcount\ranval
+
+\ifx\m!systems\undefined \def\m!systems{systems} \fi
+
+\def\nextrandom
+  {\begingroup
+   \ifnum\randomi<\plusone % then initialize with time
+     \global\randomi\time
+     \global\multiply\randomi388 \global\advance\randomi\year
+     \global\multiply\randomi 31 \global\advance\randomi\day
+     \global\multiply\randomi 97 \global\advance\randomi\month
+     \writestatus\m!systems{randomizer starts with \the\randomi}%
+     \nextrandom \nextrandom \nextrandom
+   \fi
+   \!!countd\randomi
+   \divide\!!countd 127773 % modulus = multiplier * 127773 + 2836
+   \!!countc\!!countd
+   \multiply\!!countd 127773
+   \global\advance\randomi-\!!countd % random mod 127773
+   \global\multiply\randomi 16807
+   \multiply\!!countc 2836
+   \global\advance\randomi-\!!countc\relax
+   \ifnum\randomi<\zerocount
+     \global\advance\randomi 2147483647
+   \fi
+   \endgroup}
+
+\def\setrannum#1#2#3% count register, minimum, maximum
+  {\!!counta#3%
+   \advance\!!counta-#2%
+   \advance\!!counta\plusone
+   \!!countb 2147483645 %  =  m - 2  =  2^{31} - 3
+   \divide\!!countb\!!counta
+   \getr@nval
+   \advance\ranval#2%
+   #1\ranval}
+
+\def\setrandim#1#2#3% dimen register, minimum length, maximum length
+  {\!!dimenc#2%
+   \!!dimend#3%
+   \setrannum\ranval\!!dimenc\!!dimend
+   #1\ranval\s!sp\relax} % \s!sp not needed
+
+\def\getr@nval % The values in \!!counta and \!!countb are parameters
+  {\nextrandom
+   \ranval\randomi
+   \advance\ranval\minusone
+   \divide\ranval\!!countb
+   \ifnum\ranval<\!!counta \else
+     \expandafter\getr@nval
+   \fi}
+
+\protect \endinput