I had a look in the manual of QGIS and I also browsed the Internet to find some useful information about the geometric functions of the field calculator.

I've found How to use the Intersects function in the Field Calculator of QGIS? but I'm still confused.

Does anyone have some practical examples to add?

I think all these functions could be very useful, but at the moment, their usability is quite difficult for a 'normal' user.

closed as too broad by PolyGeo Nov 22 '17 at 20:53

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • Could you add some specific examples of what kind of geometric functions you'd like to do, to a specific dataset? You may find that the operations you'd like to do aren't appropriate for individual fields and rows in a vector layer. – Simbamangu Oct 17 '14 at 7:03
  • suppose that I want a new field for my point layer with 2 values: 1 (or true) if the layer is less then 100 meters away from another point else 0 (or false). – matteo Oct 17 '14 at 11:11
  • For that example, you could use the Distance Matrix or the Distance to nearest hub functions to calculate the distance between points and then add a new column in the field calculator with an expression such as: CASE WHEN "Field_1" < 100 THEN 'True' ELSE 'False' END – Joseph Oct 20 '14 at 9:35
  • Although you can find some examples/tutorials by browsing the internet, your best source is probably right here (GIS StackExchange) as all sorts of problems are discussed with using the Field Calculator. – Joseph Oct 20 '14 at 10:21