Plots an azimuth raster using arrows.

Description

Plots an azimuth raster using arrows.

Usage

1
2
3
4
5
6
  plot_azimuth(azimuth_raster, basemap_raster,
    magnitude_raster, max_arrows_per_dim = 25,
    arrowfun = arrows, arrow.ex, length = 0.05,
    magnitude_stetch = c(0.2, 0.8),
    azimuth_raster_aggregate_method = "ngb",
    magnitude_raster_aggregate_method, na.rm = TRUE)

Arguments

azimuth_raster

RasterLayer. A raster with azimuth values in units of radians.

basemap_raster

RasterLayer. The underlying image (defaults to azimuth_raster).

magnitude_raster

RasterLayer. An optional raster which is used to scale the arrow lengths.

max_arrows_per_dim

Numeric. The maximum number of arrows to display in the longest dimension.

arrowfun

The arrow function to use (see ?arrow.plot).

arrow.ex

Numeric. Controls the length of the arrows (see arrow.plot). In general, don't set this as the length will be chosen based on the arrow spacing.

length

Numeric. Length of the edges of the arrow head (in inches).

magnitude_stetch

Ignore. Not currently working.

azimuth_raster_aggregate_method

Character. Function used when resampling the azimuth raster. Defaults to "ngb" (nearest neighbor), but can be "pa" (pixel aggregate).

magnitude_raster_aggregate_method

Character. Function used when resampling the magnitude raster. Defaults to "ngb" (nearest neighbor), but can be "pa" (pixel aggregate).

na.rm

Logical. Remove NAs when aggregate_method="pa"?

Author(s)

Jonathan A. Greenberg STARStools@estarcion.net

See Also

arrow.plot,arrows

Examples

1
2
3
4
5
6
tahoe_lidar_bareearth <- raster(system.file("external/tahoe_lidar_bareearth.tif", package="STARStools"))
tahoe_lidar_bareearth_azimuth <- slopeAspect(tahoe_lidar_bareearth,out=c('aspect'),unit='radians')
# Azimuth plot with 25 arrows in the longest direction.
plot_azimuth(azimuth_raster=tahoe_lidar_bareearth_azimuth,basemap_raster=tahoe_lidar_bareearth,magnitude_raster=tahoe_lidar_bareearth,max_arrows_per_dim=25)
# Azimuth plot with 10 arrows in the longest direction.
plot_azimuth(azimuth_raster=tahoe_lidar_bareearth_azimuth,basemap_raster=tahoe_lidar_bareearth,magnitude_raster=tahoe_lidar_bareearth,max_arrows_per_dim=10)

Want to suggest features or report bugs for rdrr.io? Use the GitHub issue tracker.