GeoCSV: Unterschied zwischen den Versionen
Aus Geoinformation HSR
Stefan (Diskussion | Beiträge) K (→GeoCSV file format specification) |
Stefan (Diskussion | Beiträge) K |
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* Data types (if supported from source or target system): See CSVT file format specification. | * Data types (if supported from source or target system): See CSVT file format specification. | ||
* Coordinate system is WGS84 (EPSG:4326) by default. | * Coordinate system is WGS84 (EPSG:4326) by default. | ||
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=== GeoCSV file format specification === | === GeoCSV file format specification === | ||
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Common restrictions: | Common restrictions: | ||
| − | * All values within one table are in the same coordinate reference system ([[CRS]]) | + | * There is only one geometry column allowed per sheet. |
| − | + | * All geometry values within one table are in the same coordinate reference system ([[CRS]]). | |
=== CSVT file format specification === | === CSVT file format specification === | ||
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* Date ("YYYY-MM-DD"), Time ("HH:MM:SS+nn") and DateTime (YYYY-MM-DD HH:MM:SS+nn) | * Date ("YYYY-MM-DD"), Time ("HH:MM:SS+nn") and DateTime (YYYY-MM-DD HH:MM:SS+nn) | ||
| − | See also http://www.gdal.org/drv_csv.html section with .csvt extension. | + | Notes: |
| + | * The geometry types are a kind of subtype: easting and northing values are stored as float, option WKT is stored in one column of type String. | ||
| + | * See also http://www.gdal.org/drv_csv.html section with .csvt extension. | ||
Version vom 30. April 2015, 16:18 Uhr
Specification of a 'modern' CSV with a geometry extension of either two easting/northing colums or one WKT column!
CSV file format specification
- Encoding is UTF-8 by default.
- First row contains attribute names separated by a => delimiter.
- Following rows are contains values separated by a => delimiter.
- Delimiter is semicolon (;) by default.
- Strings are enclosed by parantheses, to allow delimiters inside (e.g. "string").
- Data types (if supported from source or target system): See CSVT file format specification.
- Coordinate system is WGS84 (EPSG:4326) by default.
GeoCSV file format specification
GeoCSV is based on CSV. The extension comes with two variants: Options easting/northing and Options WKT.
Options "easting/northing" (similar to x/y in mathematics):
- Geometry Point type as two neighboring columns of type Float: one containing the easting coordinate, and one containing northing coordinate separated by the common delimiter.
- Example for the two easting/northing columnts "47.2274;8.8249".
- This option supports only Points.
Options WKT:
- It' one single column of type String containing a constructor, like for example: "POINT (47.2274,8.8249)".
- This option supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon.
- WKT ("Well Known Text") is originally defined by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access specification (also ISO SQL/MM). See e.g. http://en.wikipedia.org/wiki/Well-known_text
Common restrictions:
- There is only one geometry column allowed per sheet.
- All geometry values within one table are in the same coordinate reference system (CRS).
CSVT file format specification
Field/column types (if supported from source or target system):
- Integer
- Real
- String
- Date ("YYYY-MM-DD"), Time ("HH:MM:SS+nn") and DateTime (YYYY-MM-DD HH:MM:SS+nn)
Notes:
- The geometry types are a kind of subtype: easting and northing values are stored as float, option WKT is stored in one column of type String.
- See also http://www.gdal.org/drv_csv.html section with .csvt extension.
