Public Domain extensions
for ArcView GIS
reviewed by Klaus Jacobi |
The following are some basic but extremely useful functions.
One does not need to write Avenue code to use them - they are applied under Edit Table - Field - Calculate
Function name | Shape Class | Field type | Explantion | Hint |
---|---|---|---|---|
rec | all | numeric | produces record number | rec starts from 0, therefore use (rec +1) to produce consecutive numbers starting from 1 |
[shape].getx | point | numeric | produces x coordinate of a point | |
[shape].gety | point | numeric | produces y coordinate | |
[shape].returncenter.getx | polygon | numeric | produces x coordinate of center of shape extend | This does not produce the true centroid! Details are given in this explanation by Bill Huber. |
[shape].returncenter.gety | polygon | numeric | produces y coordinate of center of shape extend | |
[shape].returnarea | polygon | numeric | produces area of polygon in map units | |
[shape].returnlength | line | numeric | produces length of polyline in map units | |
[shape].returnextent.gettop | polygon,
line |
numeric | produces the maximum y value of a shapefile | |
[shape].returnextent.getright | polygon,
line |
numeric | produces the maximum x value of a shapefile | |
[shape].returnextent.getbottom | polygon,
line |
numeric | produces the minimum y value of a shapefile | |
[shape].returnextent.getleft | polygon,
line |
numeric | produces the minimum x value of a shapefile |
Whenever I got stuck with ArcView's internal help system, I visited the ArcView Knowledge Base. It was a database of the answers (SUM) of the ArcView-L mailing list. Usually I could find there a solution for my question. Unfortunately, it is now offline. The Only alternative is the ESRI Support Center, which has a nice RSS feed, but relates nowadays mainly to ArcGIS.
status: 11.03.2007