Index: description.html =================================================================== RCS file: /home/grass/grassrepository/grass6/vector/v.to.points/description.html,v retrieving revision 1.6 diff -u -r1.6 description.html --- description.html 26 Aug 2006 18:22:29 -0000 1.6 +++ description.html 27 Sep 2006 02:46:23 -0000 @@ -14,10 +14,33 @@ v.segment.

-The -v parameter is used to digitize points that fall on the line's vertices only. +The type parameter is used to control which input vector geometry types to convert into points. +Some caveats to consider about this parameter: +

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  • +Points and centroids can be considered as "lines" with only one node. Consequently, the result of selecting point or +centroid as the type parameter is that all points/centroids get written into the output vector. The +original category numbers of the input points/centroids get written to the 'lcat' attribute in layer 2 +of the output vector. All values for along are zero in the output vector, as only point geometry was used for input +(there is no linear distance to calculate along, as each point/centroid is the start and end of its own "line". +

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  • +Boundaries are treated as lines, with points getting interpolated along the boundary perimeter according to dmax. If two +adjoining polygons share a topological boundary, the boundary only gets converted to points once. +

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  • +If the type paramter is set to area, the boundary of each area is converted to points regardless of whether +or not there is a topological boundary between adjacent areas. In other words, the common boundary of two adjoining areas, +for example, gets converted to points twice. The centroid is not converted to a point in the output vector for type=area. +

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    +The -v flag is used to digitize points that fall on the line's vertices only. dmax is ignored in this case.

    -If the -i flag is used in conjunction with the -v parameter, v.to.points will digitize points +If the -i flag is used in conjunction with the -v flag, v.to.points will digitize points on the line vertices, as well as interpolate points between line vertices using dmax as the maximum allowable spacing.