Re: [Qgis-user] nodata and raster calc

Hi, In 99 % of what I do, treating nodata in any other way than a data mask would be severely detrimental to my results. This would include OR and AND. (The scientific equivalence of “Do you want it eat pizza or ‘I don’t know’? or Do you want to eat pizza or nothing?” are two different valid qu

Re: [Qgis-user] nodata and raster calc

In fact I would always expect nodata. nodata is what it says: no data. How can one calculate or generate new values with one unknown term. Especially in the case of boolean. Lets take an example from real life. You have the information of wet or not wet area. In the case of wet you have to reduc

Re: [Qgis-user] nodata and raster calc

nodata + 1 = nodata nodata * 1 = nodata nodata AND 1 = nodata nodata OR 1 = 1 nodata + 0 = nodata nodata * 0 = nodata nodata AND 0 = 0 nodata OR 0 = nodata Håvard On 11. feb. 2019 09:47, st_kie...@web.de wrote: I absolutely agree. For the Discussion. nodata is a valuable information, and is g

Re: [Qgis-user] nodata and raster calc

I absolutely agree. For the Discussion. nodata is a valuable information, and is getting lost when dealing as desired value. Although the OR part needs more Discussion. For consistency that has to be nodata as well. What about nodata OR 0? In my opinion nodata always needs a discrete treatment

Re: [Qgis-user] nodata and raster calc

On 11/02/2019 10:42, Tim Sutton wrote: Hi On 11 Feb 2019, at 10:38, Havard Tveite wrote: nodata + 1 = nodata nodata * 1 = nodata nodata AND 1 = nodata

Re: [Qgis-user] nodata and raster calc

I've thought that AND and OR are boolean operators and will produce TRUE (1) or FALSE (0) nodata + 1 = nodata nodata * 1 = nodata nodata AND 1 = 0 (false) nodata OR 1 = 1 (true) Mit freundlichen Grüßen Stefan Giese Projektleiter/Consultant ***

Re: [Qgis-user] nodata and raster calc

Hi > On 11 Feb 2019, at 10:38, Havard Tveite wrote: > > nodata + 1 = nodata > nodata * 1 = nodata > nodata AND 1 = nodata > nodata OR 1 = 1 Hmm yes, the OR case should return one! Regards Tim --- Tim Sutton t...@qgis.org ___ Qgis-user

Re: [Qgis-user] nodata and raster calc

nodata + 1 = nodata nodata * 1 = nodata nodata AND 1 = nodata nodata OR 1 = 1 Håvard On 11. feb. 2019 03:11, Nyall Dawson wrote: Hey all, I'm seeking some feedback on whether our current handling of nodata pixels in the raster calculator is correct, or (my suspicion) annoying and limiting. Cu

Re: [Qgis-user] nodata and raster calc

On 2/10/2019 7:11 PM, Nyall Dawson wrote: > Hey all, > > I'm seeking some feedback on whether our current handling of nodata > pixels in the raster calculator is correct, or (my suspicion) annoying > and limiting. > > Currently, we treat nodata pixels the same as a "NULL" value in SQL -- > so ANY f

[Qgis-user] nodata and raster calc

Hey all, I'm seeking some feedback on whether our current handling of nodata pixels in the raster calculator is correct, or (my suspicion) annoying and limiting. Currently, we treat nodata pixels the same as a "NULL" value in SQL -- so ANY function or operation with nodata as an input results in