createMeasurements.php

<?php

class WeatherStation {
    private $id;
    private $meanTemperature;

    public function __construct($id, $meanTemperature) {
        $this->id = $id;
        $this->meanTemperature = $meanTemperature;
    }

    public function measurement() {
        $m = $this->gauss_ms($this->meanTemperature, 10);
        return round($m * 10) / 10.0;
    }

    // PHP lacks a native Gaussian/normal distribution function, so we implement the Box-Muller transform
    private function gauss_ms($mean, $stdDev) {
        $u1 = mt_rand() / mt_getrandmax();
        $u2 = mt_rand() / mt_getrandmax();
        $randStdNormal = sqrt(-2 * log($u1)) * sin(2 * pi() * $u2);
        return $mean + $stdDev * $randStdNormal;
    }

    public function getId() {
        return $this->id;
    }
}

function createMeasurements($numRecords) {
    $measurementFile = './measurements.txt';
    $start = microtime(true);

    // Hardcoded data
    $stations = [
        new WeatherStation("Abha", 18.0),
        new WeatherStation("Abidjan", 26.0),
        new WeatherStation("Abéché", 29.4),
        new WeatherStation("Accra", 26.4),
        new WeatherStation("Addis Ababa", 16.0),
        new WeatherStation("Adelaide", 17.3),
        new WeatherStation("Aden", 29.1),
        new WeatherStation("Ahvaz", 25.4),
        new WeatherStation("Albuquerque", 14.0),
        new WeatherStation("Alexandra", 11.0),
        new WeatherStation("Alexandria", 20.0),
        new WeatherStation("Algiers", 18.2),
        new WeatherStation("Alice Springs", 21.0),
        new WeatherStation("Almaty", 10.0),
        new WeatherStation("Amsterdam", 10.2),
        new WeatherStation("Anadyr", -6.9),
        new WeatherStation("Anchorage", 2.8),
        new WeatherStation("Andorra la Vella", 9.8),
        new WeatherStation("Ankara", 12.0),
        new WeatherStation("Antananarivo", 17.9),
        new WeatherStation("Antsiranana", 25.2),
        new WeatherStation("Arkhangelsk", 1.3),
        new WeatherStation("Ashgabat", 17.1),
        new WeatherStation("Asmara", 15.6),
        new WeatherStation("Assab", 30.5),
        new WeatherStation("Astana", 3.5),
        new WeatherStation("Athens", 19.2),
        new WeatherStation("Atlanta", 17.0),
        new WeatherStation("Auckland", 15.2),
        new WeatherStation("Austin", 20.7),
        new WeatherStation("Baghdad", 22.77),
        new WeatherStation("Baguio", 19.5),
        new WeatherStation("Baku", 15.1),
        new WeatherStation("Baltimore", 13.1),
        new WeatherStation("Bamako", 27.8),
        new WeatherStation("Bangkok", 28.6),
        new WeatherStation("Bangui", 26.0),
        new WeatherStation("Banjul", 26.0),
        new WeatherStation("Barcelona", 18.2),
        new WeatherStation("Bata", 25.1),
        new WeatherStation("Batumi", 14.0),
        new WeatherStation("Beijing", 12.9),
        new WeatherStation("Beirut", 20.9),
        new WeatherStation("Belgrade", 12.5),
        new WeatherStation("Belize City", 26.7),
        new WeatherStation("Benghazi", 19.9),
        new WeatherStation("Bergen", 7.7),
        new WeatherStation("Berlin", 10.3),
        new WeatherStation("Bilbao", 14.7),
        new WeatherStation("Birao", 26.5),
        new WeatherStation("Bishkek", 11.3),
        new WeatherStation("Bissau", 27.0),
        new WeatherStation("Blantyre", 22.2),
        new WeatherStation("Bloemfontein", 15.6),
        new WeatherStation("Boise", 11.4),
        new WeatherStation("Bordeaux", 14.2),
        new WeatherStation("Bosaso", 30.0),
        new WeatherStation("Boston", 10.9),
        new WeatherStation("Bouaké", 26.0),
        new WeatherStation("Bratislava", 10.5),
        new WeatherStation("Brazzaville", 25.0),
        new WeatherStation("Bridgetown", 27.0),
        new WeatherStation("Brisbane", 21.4),
        new WeatherStation("Brussels", 10.5),
        new WeatherStation("Bucharest", 10.8),
        new WeatherStation("Budapest", 11.3),
        new WeatherStation("Bujumbura", 23.8),
        new WeatherStation("Bulawayo", 18.9),
        new WeatherStation("Burnie", 13.1),
        new WeatherStation("Busan", 15.0),
        new WeatherStation("Cabo San Lucas", 23.9),
        new WeatherStation("Cairns", 25.0),
        new WeatherStation("Cairo", 21.4),
        new WeatherStation("Calgary", 4.4),
        new WeatherStation("Canberra", 13.1),
        new WeatherStation("Cape Town", 16.2),
        new WeatherStation("Changsha", 17.4),
        new WeatherStation("Charlotte", 16.1),
        new WeatherStation("Chiang Mai", 25.8),
        new WeatherStation("Chicago", 9.8),
        new WeatherStation("Chihuahua", 18.6),
        new WeatherStation("Chișinău", 10.2),
        new WeatherStation("Chittagong", 25.9),
        new WeatherStation("Chongqing", 18.6),
        new WeatherStation("Christchurch", 12.2),
        new WeatherStation("City of San Marino", 11.8),
        new WeatherStation("Colombo", 27.4),
        new WeatherStation("Columbus", 11.7),
        new WeatherStation("Conakry", 26.4),
        new WeatherStation("Copenhagen", 9.1),
        new WeatherStation("Cotonou", 27.2),
        new WeatherStation("Cracow", 9.3),
        new WeatherStation("Da Lat", 17.9),
        new WeatherStation("Da Nang", 25.8),
        new WeatherStation("Dakar", 24.0),
        new WeatherStation("Dallas", 19.0),
        new WeatherStation("Damascus", 17.0),
        new WeatherStation("Dampier", 26.4),
        new WeatherStation("Dar es Salaam", 25.8),
        new WeatherStation("Darwin", 27.6),
        new WeatherStation("Denpasar", 23.7),
        new WeatherStation("Denver", 10.4),
        new WeatherStation("Detroit", 10.0),
        new WeatherStation("Dhaka", 25.9),
        new WeatherStation("Dikson", -11.1),
        new WeatherStation("Dili", 26.6),
        new WeatherStation("Djibouti", 29.9),
        new WeatherStation("Dodoma", 22.7),
        new WeatherStation("Dolisie", 24.0),
        new WeatherStation("Douala", 26.7),
        new WeatherStation("Dubai", 26.9),
        new WeatherStation("Dublin", 9.8),
        new WeatherStation("Dunedin", 11.1),
        new WeatherStation("Durban", 20.6),
        new WeatherStation("Dushanbe", 14.7),
        new WeatherStation("Edinburgh", 9.3),
        new WeatherStation("Edmonton", 4.2),
        new WeatherStation("El Paso", 18.1),
        new WeatherStation("Entebbe", 21.0),
        new WeatherStation("Erbil", 19.5),
        new WeatherStation("Erzurum", 5.1),
        new WeatherStation("Fairbanks", -2.3),
        new WeatherStation("Fianarantsoa", 17.9),
        new WeatherStation("Flores,  Petén", 26.4),
        new WeatherStation("Frankfurt", 10.6),
        new WeatherStation("Fresno", 17.9),
        new WeatherStation("Fukuoka", 17.0),
        new WeatherStation("Gabès", 19.5),
        new WeatherStation("Gaborone", 21.0),
        new WeatherStation("Gagnoa", 26.0),
        new WeatherStation("Gangtok", 15.2),
        new WeatherStation("Garissa", 29.3),
        new WeatherStation("Garoua", 28.3),
        new WeatherStation("George Town", 27.9),
        new WeatherStation("Ghanzi", 21.4),
        new WeatherStation("Gjoa Haven", -14.4),
        new WeatherStation("Guadalajara", 20.9),
        new WeatherStation("Guangzhou", 22.4),
        new WeatherStation("Guatemala City", 20.4),
        new WeatherStation("Halifax", 7.5),
        new WeatherStation("Hamburg", 9.7),
        new WeatherStation("Hamilton", 13.8),
        new WeatherStation("Hanga Roa", 20.5),
        new WeatherStation("Hanoi", 23.6),
        new WeatherStation("Harare", 18.4),
        new WeatherStation("Harbin", 5.0),
        new WeatherStation("Hargeisa", 21.7),
        new WeatherStation("Hat Yai", 27.0),
        new WeatherStation("Havana", 25.2),
        new WeatherStation("Helsinki", 5.9),
        new WeatherStation("Heraklion", 18.9),
        new WeatherStation("Hiroshima", 16.3),
        new WeatherStation("Ho Chi Minh City", 27.4),
        new WeatherStation("Hobart", 12.7),
        new WeatherStation("Hong Kong", 23.3),
        new WeatherStation("Honiara", 26.5),
        new WeatherStation("Honolulu", 25.4),
        new WeatherStation("Houston", 20.8),
        new WeatherStation("Ifrane", 11.4),
        new WeatherStation("Indianapolis", 11.8),
        new WeatherStation("Iqaluit", -9.3),
        new WeatherStation("Irkutsk", 1.0),
        new WeatherStation("Istanbul", 13.9),
        new WeatherStation("İzmir", 17.9),
        new WeatherStation("Jacksonville", 20.3),
        new WeatherStation("Jakarta", 26.7),
        new WeatherStation("Jayapura", 27.0),
        new WeatherStation("Jerusalem", 18.3),
        new WeatherStation("Johannesburg", 15.5),
        new WeatherStation("Jos", 22.8),
        new WeatherStation("Juba", 27.8),
        new WeatherStation("Kabul", 12.1),
        new WeatherStation("Kampala", 20.0),
        new WeatherStation("Kandi", 27.7),
        new WeatherStation("Kankan", 26.5),
        new WeatherStation("Kano", 26.4),
        new WeatherStation("Kansas City", 12.5),
        new WeatherStation("Karachi", 26.0),
        new WeatherStation("Karonga", 24.4),
        new WeatherStation("Kathmandu", 18.3),
        new WeatherStation("Khartoum", 29.9),
        new WeatherStation("Kingston", 27.4),
        new WeatherStation("Kinshasa", 25.3),
        new WeatherStation("Kolkata", 26.7),
        new WeatherStation("Kuala Lumpur", 27.3),
        new WeatherStation("Kumasi", 26.0),
        new WeatherStation("Kunming", 15.7),
        new WeatherStation("Kuopio", 3.4),
        new WeatherStation("Kuwait City", 25.7),
        new WeatherStation("Kyiv", 8.4),
        new WeatherStation("Kyoto", 15.8),
        new WeatherStation("La Ceiba", 26.2),
        new WeatherStation("La Paz", 23.7),
        new WeatherStation("Lagos", 26.8),
        new WeatherStation("Lahore", 24.3),
        new WeatherStation("Lake Havasu City", 23.7),
        new WeatherStation("Lake Tekapo", 8.7),
        new WeatherStation("Las Palmas de Gran Canaria", 21.2),
        new WeatherStation("Las Vegas", 20.3),
        new WeatherStation("Launceston", 13.1),
        new WeatherStation("Lhasa", 7.6),
        new WeatherStation("Libreville", 25.9),
        new WeatherStation("Lisbon", 17.5),
        new WeatherStation("Livingstone", 21.8),
        new WeatherStation("Ljubljana", 10.9),
        new WeatherStation("Lodwar", 29.3),
        new WeatherStation("Lomé", 26.9),
        new WeatherStation("London", 11.3),
        new WeatherStation("Los Angeles", 18.6),
        new WeatherStation("Louisville", 13.9),
        new WeatherStation("Luanda", 25.8),
        new WeatherStation("Lubumbashi", 20.8),
        new WeatherStation("Lusaka", 19.9),
        new WeatherStation("Luxembourg City", 9.3),
        new WeatherStation("Lviv", 7.8),
        new WeatherStation("Lyon", 12.5),
        new WeatherStation("Madrid", 15.0),
        new WeatherStation("Mahajanga", 26.3),
        new WeatherStation("Makassar", 26.7),
        new WeatherStation("Makurdi", 26.0),
        new WeatherStation("Malabo", 26.3),
        new WeatherStation("Malé", 28.0),
        new WeatherStation("Managua", 27.3),
        new WeatherStation("Manama", 26.5),
        new WeatherStation("Mandalay", 28.0),
        new WeatherStation("Mango", 28.1),
        new WeatherStation("Manila", 28.4),
        new WeatherStation("Maputo", 22.8),
        new WeatherStation("Marrakesh", 19.6),
        new WeatherStation("Marseille", 15.8),
        new WeatherStation("Maun", 22.4),
        new WeatherStation("Medan", 26.5),
        new WeatherStation("Mek'ele", 22.7),
        new WeatherStation("Melbourne", 15.1),
        new WeatherStation("Memphis", 17.2),
        new WeatherStation("Mexicali", 23.1),
        new WeatherStation("Mexico City", 17.5),
        new WeatherStation("Miami", 24.9),
        new WeatherStation("Milan", 13.0),
        new WeatherStation("Milwaukee", 8.9),
        new WeatherStation("Minneapolis", 7.8),
        new WeatherStation("Minsk", 6.7),
        new WeatherStation("Mogadishu", 27.1),
        new WeatherStation("Mombasa", 26.3),
        new WeatherStation("Monaco", 16.4),
        new WeatherStation("Moncton", 6.1),
        new WeatherStation("Monterrey", 22.3),
        new WeatherStation("Montreal", 6.8),
        new WeatherStation("Moscow", 5.8),
        new WeatherStation("Mumbai", 27.1),
        new WeatherStation("Murmansk", 0.6),
        new WeatherStation("Muscat", 28.0),
        new WeatherStation("Mzuzu", 17.7),
        new WeatherStation("N'Djamena", 28.3),
        new WeatherStation("Naha", 23.1),
        new WeatherStation("Nairobi", 17.8),
        new WeatherStation("Nakhon Ratchasima", 27.3),
        new WeatherStation("Napier", 14.6),
        new WeatherStation("Napoli", 15.9),
        new WeatherStation("Nashville", 15.4),
        new WeatherStation("Nassau", 24.6),
        new WeatherStation("Ndola", 20.3),
        new WeatherStation("New Delhi", 25.0),
        new WeatherStation("New Orleans", 20.7),
        new WeatherStation("New York City", 12.9),
        new WeatherStation("Ngaoundéré", 22.0),
        new WeatherStation("Niamey", 29.3),
        new WeatherStation("Nicosia", 19.7),
        new WeatherStation("Niigata", 13.9),
        new WeatherStation("Nouadhibou", 21.3),
        new WeatherStation("Nouakchott", 25.7),
        new WeatherStation("Novosibirsk", 1.7),
        new WeatherStation("Nuuk", -1.4),
        new WeatherStation("Odesa", 10.7),
        new WeatherStation("Odienné", 26.0),
        new WeatherStation("Oklahoma City", 15.9),
        new WeatherStation("Omaha", 10.6),
        new WeatherStation("Oranjestad", 28.1),
        new WeatherStation("Oslo", 5.7),
        new WeatherStation("Ottawa", 6.6),
        new WeatherStation("Ouagadougou", 28.3),
        new WeatherStation("Ouahigouya", 28.6),
        new WeatherStation("Ouarzazate", 18.9),
        new WeatherStation("Oulu", 2.7),
        new WeatherStation("Palembang", 27.3),
        new WeatherStation("Palermo", 18.5),
        new WeatherStation("Palm Springs", 24.5),
        new WeatherStation("Palmerston North", 13.2),
        new WeatherStation("Panama City", 28.0),
        new WeatherStation("Parakou", 26.8),
        new WeatherStation("Paris", 12.3),
        new WeatherStation("Perth", 18.7),
        new WeatherStation("Petropavlovsk-Kamchatsky", 1.9),
        new WeatherStation("Philadelphia", 13.2),
        new WeatherStation("Phnom Penh", 28.3),
        new WeatherStation("Phoenix", 23.9),
        new WeatherStation("Pittsburgh", 10.8),
        new WeatherStation("Podgorica", 15.3),
        new WeatherStation("Pointe-Noire", 26.1),
        new WeatherStation("Pontianak", 27.7),
        new WeatherStation("Port Moresby", 26.9),
        new WeatherStation("Port Sudan", 28.4),
        new WeatherStation("Port Vila", 24.3),
        new WeatherStation("Port-Gentil", 26.0),
        new WeatherStation("Portland (OR)", 12.4),
        new WeatherStation("Porto", 15.7),
        new WeatherStation("Prague", 8.4),
        new WeatherStation("Praia", 24.4),
        new WeatherStation("Pretoria", 18.2),
        new WeatherStation("Pyongyang", 10.8),
        new WeatherStation("Rabat", 17.2),
        new WeatherStation("Rangpur", 24.4),
        new WeatherStation("Reggane", 28.3),
        new WeatherStation("Reykjavík", 4.3),
        new WeatherStation("Riga", 6.2),
        new WeatherStation("Riyadh", 26.0),
        new WeatherStation("Rome", 15.2),
        new WeatherStation("Roseau", 26.2),
        new WeatherStation("Rostov-on-Don", 9.9),
        new WeatherStation("Sacramento", 16.3),
        new WeatherStation("Saint Petersburg", 5.8),
        new WeatherStation("Saint-Pierre", 5.7),
        new WeatherStation("Salt Lake City", 11.6),
        new WeatherStation("San Antonio", 20.8),
        new WeatherStation("San Diego", 17.8),
        new WeatherStation("San Francisco", 14.6),
        new WeatherStation("San Jose", 16.4),
        new WeatherStation("San José", 22.6),
        new WeatherStation("San Juan", 27.2),
        new WeatherStation("San Salvador", 23.1),
        new WeatherStation("Sana'a", 20.0),
        new WeatherStation("Santo Domingo", 25.9),
        new WeatherStation("Sapporo", 8.9),
        new WeatherStation("Sarajevo", 10.1),
        new WeatherStation("Saskatoon", 3.3),
        new WeatherStation("Seattle", 11.3),
        new WeatherStation("Ségou", 28.0),
        new WeatherStation("Seoul", 12.5),
        new WeatherStation("Seville", 19.2),
        new WeatherStation("Shanghai", 16.7),
        new WeatherStation("Singapore", 27.0),
        new WeatherStation("Skopje", 12.4),
        new WeatherStation("Sochi", 14.2),
        new WeatherStation("Sofia", 10.6),
        new WeatherStation("Sokoto", 28.0),
        new WeatherStation("Split", 16.1),
        new WeatherStation("St. John's", 5.0),
        new WeatherStation("St. Louis", 13.9),
        new WeatherStation("Stockholm", 6.6),
        new WeatherStation("Surabaya", 27.1),
        new WeatherStation("Suva", 25.6),
        new WeatherStation("Suwałki", 7.2),
        new WeatherStation("Sydney", 17.7),
        new WeatherStation("Tabora", 23.0),
        new WeatherStation("Tabriz", 12.6),
        new WeatherStation("Taipei", 23.0),
        new WeatherStation("Tallinn", 6.4),
        new WeatherStation("Tamale", 27.9),
        new WeatherStation("Tamanrasset", 21.7),
        new WeatherStation("Tampa", 22.9),
        new WeatherStation("Tashkent", 14.8),
        new WeatherStation("Tauranga", 14.8),
        new WeatherStation("Tbilisi", 12.9),
        new WeatherStation("Tegucigalpa", 21.7),
        new WeatherStation("Tehran", 17.0),
        new WeatherStation("Tel Aviv", 20.0),
        new WeatherStation("Thessaloniki", 16.0),
        new WeatherStation("Thiès", 24.0),
        new WeatherStation("Tijuana", 17.8),
        new WeatherStation("Timbuktu", 28.0),
        new WeatherStation("Tirana", 15.2),
        new WeatherStation("Toamasina", 23.4),
        new WeatherStation("Tokyo", 15.4),
        new WeatherStation("Toliara", 24.1),
        new WeatherStation("Toluca", 12.4),
        new WeatherStation("Toronto", 9.4),
        new WeatherStation("Tripoli", 20.0),
        new WeatherStation("Tromsø", 2.9),
        new WeatherStation("Tucson", 20.9),
        new WeatherStation("Tunis", 18.4),
        new WeatherStation("Ulaanbaatar", -0.4),
        new WeatherStation("Upington", 20.4),
        new WeatherStation("Ürümqi", 7.4),
        new WeatherStation("Vaduz", 10.1),
        new WeatherStation("Valencia", 18.3),
        new WeatherStation("Valletta", 18.8),
        new WeatherStation("Vancouver", 10.4),
        new WeatherStation("Veracruz", 25.4),
        new WeatherStation("Vienna", 10.4),
        new WeatherStation("Vientiane", 25.9),
        new WeatherStation("Villahermosa", 27.1),
        new WeatherStation("Vilnius", 6.0),
        new WeatherStation("Virginia Beach", 15.8),
        new WeatherStation("Vladivostok", 4.9),
        new WeatherStation("Warsaw", 8.5),
        new WeatherStation("Washington, D.C.", 14.6),
        new WeatherStation("Wau", 27.8),
        new WeatherStation("Wellington", 12.9),
        new WeatherStation("Whitehorse", -0.1),
        new WeatherStation("Wichita", 13.9),
        new WeatherStation("Willemstad", 28.0),
        new WeatherStation("Winnipeg", 3.0),
        new WeatherStation("Wrocław", 9.6),
        new WeatherStation("Xi'an", 14.1),
        new WeatherStation("Yakutsk", -8.8),
        new WeatherStation("Yangon", 27.5),
        new WeatherStation("Yaoundé", 23.8),
        new WeatherStation("Yellowknife", -4.3),
        new WeatherStation("Yerevan", 12.4),
        new WeatherStation("Yinchuan", 9.0),
        new WeatherStation("Zagreb", 10.7),
        new WeatherStation("Zanzibar City", 26.0),
        new WeatherStation("Zürich", 9.3),
    ];

    $fileHandle = fopen($measurementFile, 'w');

    if (!$fileHandle) {
        throw new Exception("Cannot open file: " . $measurementFile);
    }

    for ($i = 0; $i < $numRecords; $i++) {
        if ($i > 0 && $i % 50000 === 0) {
            $timeElapsed = microtime(true) - $start;
            echo "Wrote $i measurements in $timeElapsed ms\n";
        }
        $station = $stations[array_rand($stations)];
        fwrite($fileHandle, $station->getId() . ";" . $station->measurement() . "\n");
    }

    fclose($fileHandle);
    $totalTime = microtime(true) - $start;
    echo "Created file with $numRecords measurements in $totalTime ms\n";
}

// Usage example, passing argument from command line
if ($argc !== 2) {
    echo "Usage: create_measurements.php <number of records to create>\n";
    exit(1);
}

try {
    $size = (int) $argv[1];
    createMeasurements($size);
} catch (Exception $e) {
    echo "An error occurred: " . $e->getMessage() . "\n";
    exit(1);
}