Get or set the projection of a LAS* object with the function projection
. Functions epsg
and wkt
are reserved for advanced users (see details).
epsg(object, ...)epsg(object) <- value
wkt(object, ...)
wkt(object) <- value
# S4 method for LASheader
projection(x, asText = TRUE)
# S4 method for LASheader
crs(x, asText = FALSE)
# S4 method for LASheader
epsg(object, ...)
# S4 method for LASheader
epsg(object) <- value
# S4 method for LASheader
wkt(object, ...)
# S4 method for LASheader
wkt(object) <- value
# S4 method for LAS
projection(x) <- value
# S4 method for LAS
crs(x, ...) <- value
# S4 method for LAS
epsg(object)
# S4 method for LAS
epsg(object) <- value
# S4 method for LAS
wkt(object)
# S4 method for LAS
wkt(object) <- value
An object of class LAS or eventually LASheader (regular users don't need to manipulate LASheader objects).
Unused.
A CRS
object or a proj4string
string for functionprojection
.
An EPSG code as integer for function epsg
. A WKT
string for function wkt
.
logical. If TRUE, the projection is returned as text. Otherwise a CRS object is returned.
There are two ways to store the CRS of a point cloud in a LAS file:
Store an EPSG code (for LAS 1.0 to 1.4)
Store a WTK string (for LAS 1.4)
On the other hand, all spatial R packages use a proj4string
to store the CRS. This is why
the CRS is duplicated in a LAS object. The information belongs within the header in a format that
can be written in a LAS file and in the slot proj4string
in a format that can be understood
by R packages.
projection<-
: updates the CRS from a proj4string
. It updates the header either
with the EPSG code for LAS formats < 1.4 or with a WKT string for LAS format 1.4 and updates the
proj4string
slot. This function should always be preferred.
epsg<-
: updates the CRS from an EPSG code. It adds the EPSG code in the header and updates
the proj4string
slot.
wkt<-
: updates the CRS from a WKT string. It adds the WKT string in the header and updates
the proj4string
slot.
projection
: reads the proj4string
from the proj4string
slot.
epsg
: reads the epsg code from the header.
wkt
: reads the WKT string from the header.
crs
and crs<-
are equivalent to projection
# NOT RUN {
LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
las <- readLAS(LASfile)
crs <- sp::CRS("+init=epsg:26918")
projection(las)
projection(las) <- crs
# }
Run the code above in your browser using DataLab