GeoCSV: Unterschied zwischen den Versionen
Aus Geoinformation HSR
Stefan (Diskussion | Beiträge) K |
Stefan (Diskussion | Beiträge) K (→Example) |
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Zeile 55: | Zeile 55: | ||
=== Example === | === Example === | ||
+ | |||
+ | <pre> | ||
+ | id;name;amount;remarks;geom | ||
+ | 1;Adam;2.1;Mathe;point(10 20) | ||
+ | 2;Eva;2.2;Sport;point(30 40) | ||
+ | 3;"Jimmy;Muff";2.3;;point(50 60) | ||
+ | </pre> | ||
+ | |||
+ | repräsentiert die folgende Tabelle: | ||
+ | |||
+ | {|class="wikitable" | ||
+ | |- | ||
+ | ! id | ||
+ | ! name | ||
+ | ! amount | ||
+ | ! remarks | ||
+ | ! geom | ||
+ | |- | ||
+ | | 1 | ||
+ | | Adam | ||
+ | | 2.1 | ||
+ | | Französisch | ||
+ | | point(10 20) | ||
+ | |- | ||
+ | | 2 | ||
+ | | Eva | ||
+ | | 2.2 | ||
+ | | "Jimmy;Muff" | ||
+ | | point(30 40) | ||
+ | |- | ||
+ | | 2 | ||
+ | | Jim | ||
+ | | 2.3 | ||
+ | | | ||
+ | | point(50 60) | ||
+ | |} |
Version vom 1. Mai 2015, 01:35 Uhr
Specification of the tabular file format CSV (Comma Separated Values) with a geometry extension!
Inhaltsverzeichnis
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.
Notes:
- End-of-lines are: CR, LF or CR/LF.
- All rows have same number of attributes.
- Line Breaks in (String) fields are disallowed.
- Calculations are possible
GeoCSV file format specification
GeoCSV is based on CSV. The extension comes with two variants: Options easting/northing and Options WKT.
Option "easting/northing" (longitude/latitude, 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 "8.8249;47.2274".
- This option supports only Points.
Option WKT:
- It' one single column of type String containing a constructor, like for example: "POINT (8.8249 47.2274)".
- 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:
- Coordinate system is WGS84 (EPSG:4326) by default.
- 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, case insensitive (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)
- (lon/lat)
- (WKT)
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.
Software
- LibreOffice / OpenOffice / Excel
- OGR, QGIS
- Online:
- CSV-to-GeoJSON: convertcsv.com, csv2geojson
- GeoJSON-to-CSV: convertcsv.com
Example
id;name;amount;remarks;geom 1;Adam;2.1;Mathe;point(10 20) 2;Eva;2.2;Sport;point(30 40) 3;"Jimmy;Muff";2.3;;point(50 60)
repräsentiert die folgende Tabelle:
id | name | amount | remarks | geom |
---|---|---|---|---|
1 | Adam | 2.1 | Französisch | point(10 20) |
2 | Eva | 2.2 | "Jimmy;Muff" | point(30 40) |
2 | Jim | 2.3 | point(50 60) |