#!/usr/bin/perl

use strict;
use warnings;

my @values = (-10, -9, -8, -7, -6, -5, -4,
			  -3, -2, -1, -0.9, -0.8, -0.7, -0.6, -0.5, -0.4, -0.3, -0.2, -0.1,
			  0, 0.1, 0.111111, 0.12, 0.13, 0.16, 0.19, 0.2, 0.21, 0.22,
			  0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.00001, 1.001, 1.1, 1.2,
			  1.3, 1.8, 1.9, 2.000001, 2.001, 2.1, 2.11, 2.2, 2.3, 2.4,
			  3.1, 4, 5, 6, 7, 8, 9, 10,
			  1.16873493792849e-06, 1088.99977561893);

my $wval;
my $wexp;
my $wtanh;
my $wfisher;
my $we2;

# http://mathworld.wolfram.com/HyperbolicTangent.html
sub tanh($) {
	my $in = shift;

	my $a = exp($in);
	my $b = exp(-$in);

	return ($a - $b) / ($a + $b);
}

# https://support.office.com/en-us/article/FISHER-function-D656523C-5076-4F95-B87B-7741BF236C69
sub fisher($) {
	my $in = shift;
	return 0 if $in == 1;
	my $a = (1 + $in) / (1 - $in);
	return 0 if $a <= 0;
	return 0.5 * log($a);
}

sub e2($) {
	my $in = shift;
	return 0 if $in == 1;
	return 0.5 * exp((1 + $in) / (1 - $in));
}

map {
	$wval = $_;
	$wexp = exp($_);
	$wtanh = &tanh($_);
	$wfisher = &fisher($_);
	$we2 = &e2($_);
	write;
} @values;

format STDOUT_TOP =
value     exponent(e)          tanh              fisher          e2
--------- -------------------- ----------------- --------------- ---------------
.

format STDOUT =
@###.#### @######.############ @###.############ @###.########## @###.##########
$wval,   $wexp,           $wtanh,                $wfisher,       $we2
.