R crashes when executing pipeline

[wiesehahn]

I try to run a simple pipeline, but R crashes (" R encountered a fatal error") quickly after execution start.
This does not happen for the example file ( f <- system.file("extdata", "Topography.las", package="lasR")) but for any of my tested files.

# does not work
library(lasR)

f = "folder/file.las"
pipeline <- reader(f) + dtm()
exec(pipeline)

So it seems that something with my file is the problem. However, with lidR I can read and plot the file.

# this works
library(lidR)

las <- readLAS("folder/file.las")
> summary(las)
class        : LAS (v1.4 format 8)
memory       : 1.6 Gb 
extent       : 558000, 558524.9, 5724000, 5725000 (xmin, xmax, ymin, ymax)
coord. ref.  : ETRS89 / ETRS89 / UTM 32N + DHHN2016 
area         : 485764 m²
points       : 17.31 million points
density      : 35.64 points/m²
density      : 26.98 pulses/m²
File signature:           LASF 
File source ID:           0 
Global encoding:
 - GPS Time Type: Standard GPS Time 
 - Synthetic Return Numbers: no 
 - Well Know Text: CRS is WKT 
 - Aggregate Model: false 
Project ID - GUID:        00000000-0000-0000-0000-000000000000 
Version:                  1.4
System identifier:        LAStools (c) by rapidlasso GmbH 
Generating software:      las2las64 (version 200813) 
File creation d/y:        292/2023
header size:              375 
Offset to point data:     3115 
Num. var. length record:  5 
Point data format:        8 
Point data record length: 59 
Num. of point records:    17313297 
Num. of points by return: 13108155 2637306 1149427 341107 68044 8956 286 14 2 0 0 0 0 0 0 
Scale factor X Y Z:       0.001 0.001 0.001 
Offset X Y Z:             0 5e+06 0 
min X Y Z:                558000 5724000 217.37 
max X Y Z:                558524.9 5725000 310 
Variable Length Records (VLR):
   Variable Length Record 1 of 5 
       Description: by LAStools of rapidlasso GmbH 
       Tags:
          Key 1024 value 1 
          Key 3072 value 25832 
          Key 3076 value 9001 
          Key 4099 value 9001 
          Key 4096 value 7837 
   Variable Length Record 2 of 5 
       Description: RIEGL Extra Bytes 
       Extra Bytes Description:
          Distance: Distance
          Group: Group
          Normal: Normal vector 2+15+15 bits
   Variable Length Record 3 of 5 
       Description:  
       Extra Bytes Description:
          Distance: Distance
          Group: Group
          Normal: Normal vector 2+15+15 bits
   Variable Length Record 4 of 5 
       Description: TerraScan Extra Bytes 
       Extra Bytes Description:
          Distance: Distance
          Group: Group
          Normal: Normal vector 2+15+15 bits
   Variable Length Record 5 of 5 
       Description: by LAStools of rapidlasso GmbH 
       WKT OGC COORDINATE SYSTEM: COMPD_CS["ETRS89 / ETRS89 / UTM 32N + DHHN2016",PROJCS["ETRS89 / ETRS8 [...] (truncated)
Extended Variable Length Records (EVLR):  void

Any idea what might cause this problem?

[Jean-Romain]

I need one of your file. The problem is likely related to the format 1.4 maybe with the pdrf 8.

[Jean-Romain]

Reproduced with

library(lasR)
f <- system.file("extdata", "las14_prf6.laz", package="rlas")
pipeline <- reader(f) + dtm()
exec(pipeline)

[Jean-Romain]

I fixed my issue, which was related to the fact that there was 0 ground point. Maybe your issue is different. In my case the error is now

Erreur : in 'triangulate' while processing the point cloud: impossible to construct a Delaunay triangulation with 0 points

By the way the correct syntax is now (from 0.3.0)

pipeline <- reader_las() + dtm()
exec(pipeline, on = f)

reader_las() can be conveniently omitted. Do not forget to read the changelog. lasR is still maturing, the API is not definitive and may change.

[wiesehahn]

thanks, fixed it.
Forgot that the files were unclassified, with prior ground classification it works.

[wiesehahn]

By the way the correct syntax is now (from 0.3.0)

pipeline <- reader_las() + dtm()
exec(pipeline, on = f)

reader_las() can be conveniently omitted. Do not forget to read the changelog. lasR is still maturing, the API is not definitive and may change.

You might want to change this under e.g. https://r-lidar.github.io/lasR/reference/chm.html#ref-examples where its written as

f <- system.file("extdata", "Topography.las", package="lasR")
pipeline <- reader(f) + chm()

[Jean-Romain]

Thank you for reporting. I updated the doc