[GRASS5] field -> layer

Michael Barton michael.barton at asu.edu
Sun Nov 14 13:53:10 EST 2004


I'm glad you brought this up. It took me awhile to even figure out what
"field" meant, given my long association with databases. I agree that the
name should be changed. But let me ask to make sure exactly how 'field'
works to make sure I do understand it correctly now.

A set of vectors (i.e., shapes in a single vector map) can be associated
with more than one attribute table. 'Field' makes the connection between the
vectors and each of the the attribute tables. Field1 connects to the default
table, while field2, field3... connect the same vectors to other tables.

If this is correct, I suggest using the term connection or link rather than
layers. Layer can often imply a different set of vector shapes.

However, if I still don't understand how this works I hope you can set me


On 11/13/04 4:09 AM, "Radim Blazek" <blazek at itc.it> wrote:

> 'field' option is used as layer identifier in 5.7. Each
> vector can contain more layers, for example
> field=1 : forests
> field=2 : lakes
> Unfortunately the name 'field' is commonly used for table
> columns, so it is quite confusing. My suggestion is
> to use option key 'layer' instead of 'field'.
> Radim

C. Michael Barton, Professor of Anthropology
School of Human Evolution and Social Change
PO Box 872402
Arizona State University
Tempe, AZ  85287-2402

Phone: 480-965-6262
Fax: 480-965-7671
www: <www.public.asu.edu/~cmbarton>

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