v.profile.points - GRASS GIS manual

NAME

v.profile.points - Creates a profile (transect) from points

KEYWORDS

vector, points, profile, transect, lidar, point cloud

SYNOPSIS

v.profile.points

v.profile.points --help

v.profile.points [-z] [line_input=name] [coordinates=east,north[,east,north,...]] [point_input=name] [file_input=name] output=name [width=float] [--overwrite] [--help] [--verbose] [--quiet] [--ui]

Flags:

-z: Start the z coordinates at 0 instead of the actual height
--overwrite: Allow output files to overwrite existing files
--help: Print usage summary
--verbose: Verbose module output
--quiet: Quiet module output
--ui: Force launching GUI dialog

Parameters:

line_input=name: Vector map with a single line (with 2 points); Vector line prepared ahead
coordinates=east,north[,east,north,...]: Line coordinates (x,y,x,y); Two pairs of coordinates as an alternative to a vector line
point_input=name: Vector map with points; Or data source for direct OGR access
file_input=name: LAS (or LAZ) file with a point cloud; File to be imported using v.in.lidar
output=name [required]: Name for output vector map
width=float: Width of profile in map units; Default with is 5% of the profile length

DESCRIPTION
- Workflow in GUI
NOTES
EXAMPLE
AUTHOR

DESCRIPTION

v.profile.points creates profile (transect) from vector point map or a lidar point cloud stored in a LAS file.

Figure: Profile (transect) of a lidar point cloud, closer points are darker, further points are lighter

Workflow in GUI

First Map Display should contain some base layers such as point density raster or digital elevation model. First Map Display should contain the resulting profile or profiles. Optionally a grid overlay can be added. The "Zoom to selected map layers" button in the Map Display toolbar should be used to zoom to the newly created profile. The coordinates option in the Line tab can be activated, deactivated, or cleared during the work as need.

Figure: Creating the profile in GUI: running module from the top left window; selecting line points in the Map Display in the top right; resulting profile in the bottom.

NOTES

ASCII files such as CSV can be profiled after import and raster maps can be profiles after conversion to vector points. It is advantageous to limit the import or the conversion just to the area of interest to avoid unnecessary overhead.

EXAMPLE

v.profile.points input_file=.../points.las output=points_profile width=5 \
    coord=2090904,731231,2091435,731252

AUTHOR

Vaclav Petras, NCSU GeoForAll Lab

SOURCE CODE

Available at: v.profile.points source code (history)