Get information from a GeoTiff with TQL

Ward van Laatum

Hi, I'd like to use a panel to get some information out off a Geo Tiff. So, what I've done, I used the Overlay option to add Geo Tiff. Now the GeoTiff is visiable as an overlay. And now I'd like to use a TQL to get the specific information.

When I have a GeoJSON I load is as an Area. Then I use the command:
SELECT_ATTRIBUTE_WHERE_AREA_IS_X_AND_NAME_IS_SOIL_TYPE

I would like to do the same for the GEO Tiff. So I was thinking:
SELECT_ATTRIBUTE_WHERE_OVERLAY_IS_X

But this obviously doesn't work. Can you help?

Ward

Rudolf

Your first query returns the value of SOIL_TYPE for a specific (or in case of an X: all) area(s). For discrete polygons (such as areas coming from a geoJSON) which each have a singular value, that is obviously possible.

However, when dealing with grids, such as from a geoTIFF, the situation differs. There isn't a single "thing" with a specific value you can query. So instead, you need to reframe your question. For example: "what is the average SOIL_TYPE value within a given area's polygon?", or "how much surface area has a specific soil type?".

To answer these (reframed) questions, please take a quick look at our examples for TQL statements on our wiki: https://support.tygron.com/wiki/Tygron_Query_Language#Examples_for_common_use-cases