QGIS Raster Calculator for No Data Values and Thresholds (Version 3.x)

[@victorialopes6842]

you have no idea how much you helped me!! thank you so much, ive been through so many tutorials, my pc almost crashed trying so many things, i thought only python would help me (i was hopeless!! since im just a begginer at py, and dont know many pygis). but!! i could relate raster slope and green areas with this tutorial for my research final report. thanks thanks thanks

[@geospatialschool]

So glad you found this helpful! It's messages like this that make it worth making this content. If you want more helpful resources like this you can sign up for my email list: geospatialschool.com/learn-more/

[@maiya_angel]

Hi, isn't there a way to fill no data with single raster file? I want to fill the no data rasters with surrounding rasters through interpolation. Is it possible?

[@omerfarukelma9320]

yes i want that also.

[@manueltiburtini6528]

Thanks !!!! Subscribed!

[@odbilegjp]

I want to change Slope calculation logic . SO how can I do calculation that using values around ? for example , x= value[1upper of x ] + value[1down of x] / 2 . is it possible to take values around?

[@geospatialschool]

I don't think you can do that with raster calculator. You'll probably need write an algorithm with a programming language. It's easy to use Python to interface with QGIS.

[@odbilegjp]

@@geospatialschool Thank you. could you giev me a tip how to get ruster layer's dot infos to write slope logic? I am trying pyqgis . But I could take coordinate values. I am not sure it is correct or not.

[@odbilegjp]

@@geospatialschool could you give me any tips and hints how to change raster slope formula ?

[@geospatialschool]

The best way would be to open the rasters and numpy arrays. Then you can perform your own slope algorithm on the arrays. You can load rasters as arrays with GDAL, which can be accessed from the Python Console in QGIS. I have several videos that will help you do this.

[@odbilegjp]

@@geospatialschool thank you so much.your videos are so helpful !

[@ansonpang]

Thank you, this was so useful!

[@davidbalog2315]

how do I extract data(table with numbers of slope) for, for example, values from the slope of a map? please thank you.

[@geospatialschool]

Can you give me some more details? Do you want to know unique slope values, or the number of slope values in a given range?

[@davidbalog2315]

@@geospatialschool i know do slope values, i want to know the size (in square km ) of each slope. For example, from 100 km2, it is from 0 degrees to 5 degrees 10 km2. thanks.