ST_SetSkew
戻る  11.7. ラスタエディタ  次へ

名前

ST_SetSkew — 地理参照のスキュー (回転パラメーター)のX値とY値を設定します。一つだけ渡した場合には、X値とY値は同じ値に設定されます。

概要

raster ST_SetSkew(raster rast, float8 skewxy);

raster ST_SetSkew(raster rast, float8 skewx, float8 skewy);

説明

地理参照のスキュー (回転パラメーター)のX値とY値を設定します。一つだけ渡した場合には、X値とY値は同じ値に設定されます。詳細についてはWorld File (英語版WikiPedia)をご覧下さい。

例

これが最初の例です。

Code
UPDATE dummy_rast SET rast = ST_SetSkew(rast, 1, 2) WHERE rid = 1;
SELECT
    rid,
    format('(%s, %s)', skewx, skewy) AS skew,
    term,
    georef[idx] AS value
FROM (
    SELECT
        rid,
        ST_SkewX(rast) AS skewx,
        ST_SkewY(rast) AS skewy,
        string_to_array(ST_GeoReference(rast), E'\n') AS georef
    FROM dummy_rast
    WHERE rid = 1
) AS refs
CROSS JOIN (VALUES
    (1, 'scaleX'),
    (2, 'skewY'),
    (3, 'skewX'),
    (4, 'scaleY'),
    (5, 'originX'),
    (6, 'originY')
) AS parts(idx, term)
ORDER BY idx;
出力:
rid |  skew  |  term   |    value
-----+--------+---------+--------------
   1 | (1, 2) | scaleX  | 2.0000000000
   1 | (1, 2) | skewY   | 2.0000000000
   1 | (1, 2) | skewX   | 1.0000000000
   1 | (1, 2) | scaleY  | 3.0000000000
   1 | (1, 2) | originX | 0.5000000000
   1 | (1, 2) | originY | 0.5000000000
(6 rows)

これが二つ目の例で、両方の値に同じ数字を設定します。

Code
UPDATE dummy_rast SET rast = ST_SetSkew(rast, 0) WHERE rid = 1;
SELECT
    rid,
    format('(%s, %s)', skewx, skewy) AS skew,
    term,
    georef[idx] AS value
FROM (
    SELECT
        rid,
        ST_SkewX(rast) AS skewx,
        ST_SkewY(rast) AS skewy,
        string_to_array(ST_GeoReference(rast), E'\n') AS georef
    FROM dummy_rast
    WHERE rid = 1
) AS refs
CROSS JOIN (VALUES
    (1, 'scaleX'),
    (2, 'skewY'),
    (3, 'skewX'),
    (4, 'scaleY'),
    (5, 'originX'),
    (6, 'originY')
) AS parts(idx, term)
ORDER BY idx;
出力:
rid |  skew  |  term   |    value
-----+--------+---------+--------------
   1 | (0, 0) | scaleX  | 2.0000000000
   1 | (0, 0) | skewY   | 0.0000000000
   1 | (0, 0) | skewX   | 0.0000000000
   1 | (0, 0) | scaleY  | 3.0000000000
   1 | (0, 0) | originX | 0.5000000000
   1 | (0, 0) | originY | 0.5000000000
(6 rows)