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I have a catalog of just over 3000 LAZ files that I want to split into regions using clip_rectangle(). The total catalog size is 60GB. My PC has 64GB of RAM but I get an error that lidR is unable to create a 2.8GB vector when I try to create my subset.

Is the simple answer to get more RAM or is there a way to avoid this without having to add more RAM?

Here's my script:

library(lidR)
set_lidr_threads(6L)
ctg <- readLAScatalog("c:/noaa/utm/ground/")
#Make sure we plot the catalog so we can see where we want our clip regions
plot(ctg)
subset = clip_rectangle(ctg, 5550000, 2795000,570000,27972500)

enter image description here

2

clip_rectangle() extracts the region of interest as a single point-cloud. Here you are trying to load something like 100 files in R. For sure it failed and more RAM won't help. You are better to subset the LAScatalog with catalog_intersect().

subset = catalog_intersect(ctg, raster(extent(5550000, 2795000,570000,27972500)))
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  • No matter what values I use for the extents, I get the following error: Error in slot(y, "proj4string") : no slot of name "proj4string" for this object of class "Extent" – Steve Mar 28 at 2:15
  • Try with a raster. I edited my anwser – JRR Mar 28 at 9:58
  • That seems to work although I get a warning message about Non Identical CRS – Steve Mar 28 at 21:25
  • Yes indeed but it does not really matter here – JRR Mar 28 at 22:31

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