README

这是一个简单的库，用于使用FFI读取GRIB2 WMO格式。

目的

此库展示了如何使用适配libeccodes与PHP FFI扩展结合使用，以节省开发者的时间。

安装

composer require okvpn/grib2-eccodes

安装libaec-dev

apt install libaec-dev

(可选) 安装eccodes库。请参阅https://confluence.ecmwf.int/display/ECC/ecCodes+installation。

但为了简化分发，libeccodes已内置数据eccodes.tar.gz。它将被提取到tmp目录。

用法

# Get grib index data 
# https://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.<date>/<time>/atmos/gfs.t<time>z.pgrb2b.1p00.f<xxx>.idx

170:9120456:d=2023081906:RH:575 mb:3 hour fcst:
171:9195051:d=2023081906:TCDC:575 mb:3 hour fcst:
172:9235360:d=2023081906:VVEL:575 mb:3 hour fcst:
173:9325082:d=2023081906:DZDT:575 mb:3 hour fcst:
174:9400873:d=2023081906:UGRD:575 mb:3 hour fcst:
175:9480146:d=2023081906:VGRD:575 mb:3 hour fcst:
176:9560543:d=2023081906:ABSV:575 mb:3 hour fcst:
177:9632016:d=2023081906:CLWMR:575 mb:3 hour fcst:

下载Grib2存档

$curl = new CurlHttpClient();
// Select 174:9400873:d=2023081906:UGRD:575 mb:3 hour fcst:
// Use http 206 Partial Content feature to downlaod only one param
$res = $curl->request('GET', 'https://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.<date>/<time>/atmos/gfs.t<time>z.pgrb2b.1p00.f003', ['headers' => ['Range' => 'bytes=9400873-9480145']]);

file_put_contents("VGRD.p1", $res->getContent())

require_once __DIR__ . '/vendor/autoload.php';

use FFI;
use Okvpn\Grib2\Grib2Reader;
use Okvpn\Grib2\LibEccodes;

LibEccodes::$libPath = "libeccodes.so"; // . use fill path if installed eccodes to custom path

$reader = new Grib2Reader();

$data = $reader->read("VGRD.p1");

print_r($data);


$matrix = $reader->read2D("VGRD.p1", lat1: 48, lat2: 57, lon1: 13, lon2: 36);
foreach ($matrix as $i => &$vals) {
    foreach ($vals as $j => &$val) {
        $val = ($s = strlen($val = round($val))) >= 3 ? $val : $val . str_repeat(' ', 3-$s);
    }
}

输出

5   6   5   3   3   3   3   5   4   4   5   5   5   7   7   7   4   9   6   6   9   5   7   8  
5   7   5   2   0   2   2   1   -0  1   2   2   4   4   5   6   6   7   6   6   5   5   6   6  
4   6   5   3   2   2   0   0   1   2   1   1   2   3   2   2   3   1   1   1   2   2   5   4  
5   5   5   3   3   2   2   1   3   5   6   5   4   3   3   2   -0  -1  -1  -2  -2  -3  -3  -1 
6   6   5   3   3   3   2   4   4   5   4   4   4   4   2   1   0   -0  -0  -2  -1  -1  -3  -4 
5   6   6   1   2   2   2   3   4   4   3   2   3   2   2   3   0   0   -0  -2  -1  -1  -2  -3 
5   4   1   1   1   0   1   4   3   1   2   1   2   3   4   3   2   0   -1  -0  -2  -2  -2  -3 
4   1   1   1   0   1   2   2   2   1   2   2   3   2   3   3   1   0   -0  -1  -2  -3  -4  -3 
2   0   1   -1  -0  1   2   1   0   1   1   2   3   3   1   1   0   -0  0   0   -1  -3  -5  -4 
-1  -1  -3  -2  -0  -1  -2  -2  -2  -1  0   2   2   2   2   1   0   0   -0  -1  -1  -3  -5  -5 

许可证

MIT许可证。