Naming outputs by X and Y coordinates

[samuelgrubinger]

Hello. Is it possible to write lasR outputs named according to their X and Y center coordinates, as it was in lidR? I can't find this in the documentation, sorry if I missed it.
I am essentially retiling flight lines in the classification step, and would like them to be named as follows:
pipeline = reader_las() + classify_with_ivf() + classify_with_csf() + write_las(paste0(root_dir, "/output/_1_classified_points/{XCENTER}_{YCENTER}_ground.las"))

[Jean-Romain]

No it is not possible sorry.

[wiesehahn]

Hey,
I had a similar use case and you could try to solve it with something like this:

# function to get extent and center coordinate for a bunch of files
get_center <- function(path, full.names = FALSE){
  
  get_file_center <- function(file){
    fileheader <- lidR::readLASheader(file)
    
    minx = fileheader$`Min X`
    miny = fileheader$`Min Y`
    maxx = fileheader$`Max X`
    maxy = fileheader$`Max Y`
    
    meanx = as.integer(minx + 0.5*(maxx-minx))
    meany = as.integer(miny + 0.5*(maxy-miny))
    
    if (full.names == FALSE){
      file <- basename(file)
    }
    
    return(data.frame(file = file, minx, miny, maxx, maxy, meanx, meany))
    
  }
  
  f <- list.files(path, pattern = "*.laz$", full.names = TRUE)
  return(as.data.frame(do.call(rbind, lapply(f, get_file_center))))
}

# apply function on folder and rename laz files to xcenter_ycenter.laz
t <- get_center(yourfolder, full.names = T)
file.rename(from = t$file, to = fs::path(dirname(t$file), paste0(t$meanx, "_", t$meany, ".laz")))

This does not directly save the output with your desired name, but it renames files afterwards. To do this we will not read the entire files but just their headers, which might not be super correct but much quicker.

[Jean-Romain]

I will consider adding the feature. By the way lidR uses the header to assign coordinates in the name. Your solution is perfectly fine.