如何将 Circlize 弦图另存为图形对象

Question

I created a chord diagram in R using the circlize package. I noticed that this graphic is not being saved as a ggplot object. I am trying to make the graphic an object so I can export it to excel. Any suggestions?

chordDiagram(as.data.frame(ba_delivery_flow.sas7bdat), annotationTrack = "grid", preAllocateTracks =  1,
                        direction.type = "diffHeight")
circos.trackPlotRegion(track.index = 2, panel.fun = function(x, y) {
xlim = get.cell.meta.data("xlim")
ylim = get.cell.meta.data("ylim")
sector.name = get.cell.meta.data("sector.index")
circos.text(mean(xlim), ylim[1]+5, sector.name, facing = "clockwise", niceFacing = TRUE, adj = c(0, .5), cex = 1)
circos.axis(h = "top", labels.facing = "clockwise", labels.cex = 0.5, major.tick.percentage = 0.2, sector.index = sector.name, track.index = 2)

}, bg.border = NA)

Answer 1

R has two graphics systems, base and grid . ( grid is what ggplot2 and lattice are built on.) Your plot is built with base , and unfortunately base plots are not objects R, so you cannot assign them to a variable, and saving them is a little different.

To save the plot in a file, you open up a graphics device, like png , put your code to draw the plot, and then use dev.off() to close the device. Like this:

png("my_plot.png") 

## all of your plotting code

dev.off()

See ?png an argument list, and a few other devices too.

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As an aside, you can save ggplots this way too. If you have a plot object p , you can put print(p) in between the png() and the dev.off() . This is essentially what ggsave does internally.