[GRASS-dev] [bug #5254] (grass) enable v.what to report on more that one category

Request Tracker grass-bugs at intevation.de
Thu Nov 2 23:57:20 EST 2006

this bug's URL: http://intevation.de/rt/webrt?serial_num=5254

Subject: enable v.what to report on more that one category

Platform: GNU/Linux/x86
A wish for Grass 6.3?

I don't know how often situations like this might arise, however...

I have a database with over 75000 records (~30 fields/record) which is poorly georeferenced (it uses an odd alpha-numeric mapping reference involving map book pages, etc), such that locations can be defined only to the nearest 1km by 1km area. I have calculated UTM centered on the 1 km squares for each record using a spreadsheed. These 75000 records imported into Grass result in approx. 12500 points (too much data to sort on a spreadsheet).

While some data points may contain as many as 20 categories, it appears that v.what can report on only one category (the first one encountered?). It would be nice if v.what could "drill through" all categories at each point to report all data. In addition, it would be nice if a new Grass module could be developed to allow functions like mean, max, min, etc., to be done for the various fields available in this too-many-categories-per-point database, in which case some very useful surface maps could be produced.

I do not write code and so cannot contribute directly to development, but I introduce the concept here in the hope that someone who can write might find this change to v.what and/or a new function handy. I am willing to make parts of the database available for such development and can participate in testing.


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