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benchmarking/bench-axis-predict-accel.pl  view on Meta::CPAN

#!/usr/bin/perl
# benchmarking/bench-axis-predict-accel.pl
#
# Benchmarks axis-mode (classic IF) scoring/prediction under each
# acceleration backend:
#   pure_perl   -- use_c => 0                   (pure Perl tree walk)
#   c_serial    -- use_c => 1, use_openmp => 0  (C tree walk, single thread)
#   c_openmp    -- use_c => 1, use_openmp => 1  (C tree walk, OpenMP parallel)
#
# This is where the accel differences are largest: the C backend replaces
# the Perl tree walk with a tight C loop, and OpenMP distributes query
# points across cores.
#
# Sections:
#   1. Scoring method comparison  -- all 5 methods under each backend
#   2. Query set size scaling     -- where OpenMP parallelism shines
#   3. n_trees scaling            -- more trees = more work per point
#   4. Feature count (wide)       -- 2, 5, 10, 20, 50
#   5. Feature count (2-10)       -- fine-grained sweep
#
# Models are pre-trained before any timing begins.
#
# Run with:
#   perl -Ilib benchmarking/bench-axis-predict-accel.pl

use strict;
use warnings;
use lib '../lib';
use FindBin;
use lib "$FindBin::Bin";
use BenchAccel qw(wall_cmpthese);
use Algorithm::Classifier::IsolationForest;

use constant PI => 3.14159265358979;

sub gaussian {
	my ( $mu, $sigma ) = @_;
	return $mu + $sigma * sqrt( -2 * log( rand() || 1e-12 ) ) * cos( 2 * PI * rand() );
}

sub make_data {
	my ( $n, $nf ) = @_;
	my @rows = map {
		[ map { gaussian( 0, 1 ) } 1 .. $nf ]
	} 1 .. $n;
	for ( 1 .. int( $n * 0.05 ) ) {
		my $r = 5 + rand() * 3;
		push @rows, [ map { $r * ( rand() > 0.5 ? 1 : -1 ) } 1 .. $nf ];
	}
	return \@rows;
} ## end sub make_data

my $HAS_C      = $Algorithm::Classifier::IsolationForest::HAS_C;
my $HAS_OPENMP = $Algorithm::Classifier::IsolationForest::HAS_OPENMP;

# Build one model per accel config.  They share the same seed and training
# data so tree structure is identical -- only the scoring path differs.
sub build_models {
	my (%opts) = @_;
	my $data = delete $opts{_data};
	my %m;
	$m{pure_perl} = Algorithm::Classifier::IsolationForest->new( %opts, use_c => 0, )->fit($data);
	if ($HAS_C) {
		$m{c_serial} = Algorithm::Classifier::IsolationForest->new(
			%opts,
			use_c      => 1,
			use_openmp => 0,
		)->fit($data);
	}
	if ( $HAS_C && $HAS_OPENMP ) {
		$m{c_openmp} = Algorithm::Classifier::IsolationForest->new(
			%opts,
			use_c      => 1,
			use_openmp => 1,
		)->fit($data);
	}
	return \%m;
} ## end sub build_models

print "=" x 70, "\n";
print " axis-mode scoring/predict accel benchmarks\n";
print " Algorithm::Classifier::IsolationForest\n";
print "=" x 70, "\n";
printf "Backend availability: HAS_C=%d  HAS_OPENMP=%d  HAS_SIMD=%d\n",
	$HAS_C, $HAS_OPENMP,
	$Algorithm::Classifier::IsolationForest::HAS_SIMD;
print "(rates shown as calls/second wall-clock; higher is faster)\n";

# -----------------------------------------------------------------------
# 1. Scoring method comparison  (n_trees=100, 1000 query points)