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GRASS ASCII vector format specificationA vector map in GRASS native vector format may contain a mix of primitives including points, lines, boundaries, centroids, areas, faces, and kernels. The GRASS ASCII vector format may contain also a header with various metadata (see example below). The header is similar as the head file of vector binary format but
contains bounding box also. Key words are:
ORGANIZATION DIGIT DATE DIGIT NAME MAP NAME MAP DATE MAP SCALE OTHER INFO ZONE WEST EDGE EAST EDGE SOUTH EDGE NORTH EDGE MAP THRESH The body begins with the row:
VERTI:followed by records of primitives: TYPE NUMBER_OF_COORDINATES [NUMBER_OF_CATEGORIES]Everything above in [ ] is optional. The primitive codes are as follows:
The order of coordinates is
X Y [Z]In pre-GRASS 6 versions of the ASCII format, the order of coordinates was different: Y X Latitude/Longitude data may be given in a number of ways. Decimal
degrees must be positive or negative instead of using a hemisphere letter.
Mixed coordinates must use a hemisphere letter. Whole minutes and seconds
must always contain two digits (example: use 167:03:04.567; and not
167:3:4.567).
EXAMPLESORGANIZATION: GRASS Development Team DIGIT DATE: 1/9/2005 DIGIT NAME: - MAP NAME: test MAP DATE: 2005 MAP SCALE: 10000 OTHER INFO: Test polygons ZONE: 0 MAP THRESH: 0.500000 VERTI: B 6 In this case the vector map contains 2 boundaries (first boundary with 6 vertices, second with 4 vertices) without category and 2 centroids with category number 20 and 21 (layer 1). SEE ALSOv.in.ascii, v.out.ascii, v.edit, v.support SOURCE CODEAvailable at: GRASS ASCII vector format specification source code (history) Accessed: Monday Feb 24 12:19:10 2025 Main index | Vector index | Topics index | Keywords index | Graphical index | Full index © 2003-2025 GRASS Development Team, GRASS GIS 8.4.1 Reference Manual
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