Gro-Tsen

\documentclass[12pt,a4paper]{article}  % -*- coding: utf-8 -*-
\usepackage[a4paper,margin=1.5cm]{geometry}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{times}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}

Gro-Tsen

\documentclass[12pt,a4paper]{article}  % -*- coding: utf-8 -*-
\usepackage[a4paper,margin=1.5cm]{geometry}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{times}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{amsthm}

Gro-Tsen

rhosq = r^2 + nut^2
Deltasq = r^2 - 2 M r - nut^2

(* Covariant metric tensor (metric on vectors) *)
g = Simplify[{{-Deltasq/rhosq,0,0,-2 nut Cos[theta] Deltasq/rhosq},{0,rhosq/Deltasq,0,0},{0,0,rhosq,0},{-2 nut Cos[theta] Deltasq/rhosq,0,0,rhosq Sin[theta]^2 - 4 nut^2 Cos[theta]^2 Deltasq/rhosq}}]

(* Contravariant metric tensor (metric on covectors) *)
ginv = Simplify[Inverse[g]]

coords = {t,r,theta,phi}

Gro-Tsen

#! /usr/local/bin/perl -w

## This program takes a GNU tar file and produces on the standard
## output another tar file that consists only of the files whose path
## (as stored in the archive) matches the specified pattern.  No other
## treatment is performed and the output tar just consists of the
## matching bits of the input tar.

## Options are:
##   -v : Print filenames on standard error as they are being treated.

Gro-Tsen

#! /usr/local/bin/perl -w

use strict;
use warnings;
use utf8;

my %results;
my %lists;
my @revlists;
my $nblists = 0;

Gro-Tsen

Gro-Tsen

01001	46.153482/4.932753	L'Abergement-Clémenciat
01002	46.006821/5.427596	L'Abergement-de-Varey
01004	45.958184/5.374963	Ambérieu-en-Bugey
01005	45.995555/4.914269	Ambérieux-en-Dombes
01006	45.749037/5.593317	Ambléon
01007	46.002726/5.364199	Ambronay
01008	45.937040/5.331642	Ambutrix
01009	45.784362/5.655285	Andert-et-Condon
01010	45.909606/5.795569	Anglefort
01011	46.206625/5.656232	Apremont

Gro-Tsen

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>

#ifndef M_PI
#define M_PI 3.14159265358979323846264338327950288419716939937511
#endif

#ifndef DEBUG

Gro-Tsen

#! /usr/local/bin/perl -w

# Convert a decimal number to its literal expression in English.

use strict;
use warnings;
use Getopt::Std;

my %opts;
getopts("u", \%opts);

Gro-Tsen

#! /usr/local/bin/perl -w

# Generate a graphical representation of either the Stern-Brocot or
# (with option -d) the dyadic tree on the interval [0,1].
# -- David A. Madore <http://www.madore.org/~david/> 2023-12-23
# Public Domain

use strict;
use warnings;