Select image regions by plotting interactive polygons#
Last Updated: Jan 14, 2025
Description#
Plot interactive polygons on an image and retrieve the polygons coordinates.
Usage#
plotInteractivePolygons(x, width = "auto", height = "auto", ...)
Arguments#
|
A ‘ggplot’ or ‘rast’ plot object to draw polygons on |
|
An integer, defining the width/height in pixels. |
|
Graphical parameters passed on to ‘polygon’ or ‘geom_point’. |
Value#
A ‘data.table’ containing x,y coordinates from the plotted polygons.
Examples#
## Not run:
# Using a ggplot2 plot
library(ggplot2)
df <- data.frame(x = 1:5, y = 1:5)
my_plot <- ggplot(df, aes(x,y)) + geom_point()
plotInteractivePolygons(my_plot)
# Using a terra rast image
library(terra)
r = rast(system.file("ex/elev.tif", package="terra"))
plotInteractivePolygons(r)
plotInteractivePolygons(r, border = "red", lwd = 2)
# Using an image contained in Giotto object
library(Giotto)
my_spatPlot <- spatPlot2D(gobject = my_giotto_object,
show_image = TRUE,
point_alpha = 0.75,
save_plot = FALSE)
plotInteractivePolygons(my_spatPlot, height = 500)
my_polygon_coordinates <- plotInteractivePolygons(my_spatPlot, height = 500)
## End(Not run)