From 8b554f562d36c27e8c3968cf181c889dc6a09a6b Mon Sep 17 00:00:00 2001
From: e78783 <fungcheokyin@gmail.com>
Date: Tue, 17 May 2022 17:10:15 +0800
Subject: Week 165

---
 challenge-165/cheok-yin-fung/perl/ch-1.pl | 42 ++++++++++++++++++++++
 challenge-165/cheok-yin-fung/perl/ch-2.pl | 59 +++++++++++++++++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 challenge-165/cheok-yin-fung/perl/ch-1.pl
 create mode 100644 challenge-165/cheok-yin-fung/perl/ch-2.pl

diff --git a/challenge-165/cheok-yin-fung/perl/ch-1.pl b/challenge-165/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..ec333aae85
--- /dev/null
+++ b/challenge-165/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,42 @@
+#!/usr/bin/perl
+# The Weekly Challenge 165
+# Task 1 SVG
+# Usage: $ ch-1.pl < DATA > IMG_FILE_NAME.svg
+
+use v5.24.0;
+use warnings;
+use SVG;
+
+my $img = SVG->new;
+
+while (<STDIN>) {
+    chomp;
+    my @nums = split ",", $_;
+    if (scalar @nums == 2) {
+        new_point(@nums);
+    }
+    elsif (scalar @nums == 4) {
+        new_line(@nums);
+    }
+}
+
+
+
+sub new_point {
+    my ($cx, $cy) = ($_[0], $_[1]);
+    $img->circle(cx => $cx, cy => $cy, r => 2, style => {fill => 'red'});
+}
+
+
+
+sub new_line {
+    my ($x1, $y1, $x2, $y2) = ($_[0], $_[1], $_[2], $_[3]);
+    $img->line( x1 => $x1, y1 => $y1, x2 => $x2, y2 => $y2, 
+    style => {
+        'fill-opacity' => 0,
+        'stroke'       => 'green'
+    });
+}
+
+
+print $img->xmlify(-namespace=>'svg');
diff --git a/challenge-165/cheok-yin-fung/perl/ch-2.pl b/challenge-165/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..4cc8f19c0a
--- /dev/null
+++ b/challenge-165/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,59 @@
+#!/usr/bin/perl
+# The Weekly Challenge 165
+# Task 2 Line of Best Fit
+# Usage: $ ch-2.pl
+use v5.24.0;
+use warnings;
+use List::Util qw/min max sum/;
+use ARGV::OrDATA;
+
+my @points;
+
+while (<>) {
+    chomp;
+    my @new_points = /\S+/g;
+    @new_points = map { [split ",", $_]} @new_points;
+    push @points, @new_points; 
+}
+
+my $n = scalar @points;
+
+my $slope = 
+     (  $n * sum(map {$_->[0]*$_->[1]} @points)
+      - sum(map{$_->[0]} @points) * sum(map{$_->[1]} @points) )
+    / ( $n * sum(map{$_->[0]**2} @points)
+         - (sum( map { $_->[0]} @points ))**2) ;
+
+
+my $intercept =
+     ( sum( map {$_->[1]} @points ) 
+    - $slope * sum( map {$_->[0]} @points) )
+    / $n ;
+
+
+sub y_best_fit {
+    my $x = $_[0];
+    return $slope*$x + $intercept;
+}
+
+my $minx = min( map {$_->[0]} @points );
+my $maxx = max( map {$_->[0]} @points );
+
+my $line_of_best_fit = 
+    join ",", $minx,y_best_fit($minx),$maxx,y_best_fit($maxx);
+
+open FH, "> BEST_FIT_DATA" or die $!;
+say FH $line_of_best_fit;
+say FH $_->[0],",",$_->[1] for @points;
+
+system("perl ch-1.pl < BEST_FIT_DATA > new.svg"); # applicable on Linux
+
+
+
+__DATA__
+333,129  39,189 140,156 292,134 393,52  160,166 362,122  13,193
+341,104 320,113 109,177 203,152 343,100 225,110  23,186 282,102
+284,98  205,133 297,114 292,126 339,112 327,79  253,136  61,169
+128,176 346,72  316,103 124,162  65,181 159,137 212,116 337,86
+215,136 153,137 390,104 100,180  76,188  77,181  69,195  92,186
+275,96  250,147  34,174 213,134 186,129 189,154 361,82  363,89
-- 
cgit