Error in fast_quantization with DTM infinite values

[Jean-Romain]

Discussed in https://github.com/Jean-Romain/lidR/discussions/459

^{Originally posted by **CrHvG** August 11, 2021} I get the following error : ```r Error in fast_quantization(las@data[["Z"]], zscale, zoffset) : Non quantizable value outside the range of representable values of type 'int' ``` The only other mention I see on Stack Exchange references a bug that was fixed with 3.1.2, but I am using 3.1.4 and still get an error. Here is my code (las attached): ```r tmp_las <- readLAS(...xxx...) dtm = grid_terrain(tmp_las, algorithm = knnidw()) las_norm<-normalize_height(tmp_las, dtm) ``` [NIWO_2020_447000_4429000.zip](https://github.com/Jean-Romain/lidR/files/6971438/NIWO_2020_447000_4429000.zip)

[Jean-Romain]

The error is not from quantization but from grid_terrain(). Your DTM has infinite values then the normalized point cloud also have an infinite value. I'll try to fix that. Point-cloud with complex convex shape are always problematic. I need to investigate to figure out where these infinite come from.

[Jean-Romain]

After investigation there are several things to consider here.

First your DTM contained infinite values. Actually it contains NaNs that were wrongly converted to infinite. I fixed the conversion in 3.1.5 to preserve NaNs but can't yet explain why we have NaNs. So your DTM is now correct but we have another problem

tmp_las <- readLAS(LASfile)
dtm = grid_terrain(tmp_las, algorithm = knnidw())
las_norm <- normalize_height(tmp_las, dtm)
#> Error: 1 points were not normalizable because the DTM contained NA values. Process aborted. 

You have one point outside the ground points and too far to be interpolated. This points is part of 3 other outlier points classified low points (class 7). You are better to get rid of them.

tmp_las <- readLAS(LASfile, filter = "-drop_class 7")

[cingularities]

I am having the same issue.

Error in fast_quantization(las@data[["Z"]], zscale, zoffset) : 
  Non quantizable value outside the range of representable values of type 'int'

but I already loaded the file using filter = "-drop_class 7"

lidR version: 4.0.0

[Jean-Romain]

Please open an issue with a minimal reproducible example