LiDAR LAS file import into R via RSAGA
Thanks Michael Sumner rLidar works well. But how do I pass the lidar data to another SAGA module within R without saving the output of each step as a file in a whole series of SAGA module calls from R? I would like something like the dplyr %>% pipe command. Thanks Clay
On Fri, Feb 12, 2016 at 7:44 PM, Michael Sumner <mdsumner at gmail.com> wrote:
Try rLidar::readLAS as a straightforward alternative, it's not bullet proof but works fine for a lot of examples. Happy to help extend it if your format is not supported. Cheers, Mike On Fri, 12 Feb 2016 7:41 am Clay S <clayms at gmail.com> wrote:
Hi
Is it possible to import a Lidar LAS file into R with the
rsaga.geoprocessor function of the RSAGA package. The following code runs
without an error, but all I get in R is the SAGA console output.
The R code below does save a SAGA point cloud file called "test" in my
working directory. If I delete the `POINTS = "test"` parameter, then
nothing happens as expected. However, I want to work with the data in R,
and pass the point cloud to other SAGA modules. This can be done in SAGA
without having to save the point cloud. Can the same be done from R?
How can I get the point cloud imported into the R environment? Do I need
to coerce it into a matrix, data frame, or Spatial Points object?
R code:
###############
library(RSAGA)
# Set RSAGA environment.
env <- rsaga.env()
# SET WORKING DIRECTORY FIRST!!
dir <- getwd()
# Get module parameters
lasfilelist <- list.files(dir, pattern =".las$", full.names=TRUE,
recursive=FALSE)
# send command to RSAGA
test <- rsaga.geoprocessor(lib = "io_shapes_las", module = "Import LAS
Files",
param = list(FILES = lasfilelist[1], POINTS = "test",
T=TRUE, i=TRUE, a=FALSE, r=TRUE, c=FALSE,
u=FALSE,
n=TRUE, R=FALSE, G=FALSE, B=FALSE,
e=FALSE,
d=FALSE,
p=FALSE, C=FALSE, VALID=FALSE,
RGB_RANGE=FALSE),
env = env)
###################
Here is the console output (the test variable stores the same thing):
###########
library path: C:\OSGEO4~1\apps\saga\modules\io_shapes_las.dll
library name: Import/Export - LAS
tool name : Import LAS Files
author : O. Conrad, V. Wichmann (c) 2009
Parameters
Input Files: "C:/Users/whcms0/'.CPT/Tarewa/Lidar/AX300711.las"
Point Clouds: No objects
gps-time: yes
intensity: yes
scan angle: no
number of the return: yes
classification: no
user data: no
number of returns of given pulse: yes
red channel color: no
green channel color: no
blue channel color: no
edge of flight line flag: no
direction of scan flag: no
point source ID: no
rgb color: no
Check Point Validity: no
R,G,B value range: 16 bit
Parsing AX300711.las ...
Save point cloud: test...
################
Here is my env:
################
env
$workspace
[1] "."
$cmd
[1] "saga_cmd.exe"
$path
[1] "C:\\OSGeo4W64\\apps\\saga"
$modules
[1] "C:\\OSGeo4W64\\apps\\saga/modules"
$version
[1] "2.1.2"
$cores
[1] NA
$parallel
[1] FALSE
$lib.prefix
[1] ""
#################
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-- Dr. Michael Sumner Software and Database Engineer Australian Antarctic Division 203 Channel Highway Kingston Tasmania 7050 Australia