Changes between Version 4 and Version 5 of LayerAlgebra

Timestamp:

Aug 9, 2012, 11:49:52 PM (12 years ago)

Author:

Ari Jolma

Comment:

--

LayerAlgebra

@@ -23 +23 @@
 [[Image(Intersection.jpg)]]
 
-'''Figure''' An example of the intersection of two layers (a and b) created with Geoinformatica, which uses the GDAL Perl bindings. The schema of layer a is (A int) and that of b is (B int), the layer c is the result layer. The schema of c was empty when the Intersection method was called, thus it gets the schema (A int, B int). The result (c, light green) is as if a (light blue) was clipped to the rectangle in b (shown in light orange). The numbers in the map are the values of attribute A of a and c.
+'''Figure''' An example of the intersection (c) of two layers (a and b) created with Geoinformatica, which uses the GDAL Perl bindings. The schema of layer a is (A int) and that of b is (B int), the layer c is the result layer. The schema of c was empty when the Intersection method was called, thus it gets the schema (A int, B int). The result (c, light green) is as if a (light blue) was clipped to the rectangle in b (shown in light orange). The numbers in the map are the values of attribute A of a and c.
 
 == Union ==
+
+A union is a set of features, which represent areas that are in either of the operand layers.
+
+[[Image(Union.jpg)]]
+
+'''Figure''' An example of the union (c) of two layers (a and b). Note that the features have been split for the result layer. The feature 6 of the result layer is selected (its border is drawn in red).
 
 == !SymDifference ==