如何将图像叠加到ggplot上？

Question

我想从网上阅读图片。 e.g。

http://api.altmetric.com/donut/502878_64x64.png

并将其插入ggplot

的右上角

df <- data.frame(x=1:10, y=sample(1:100,10))
# a fake plot to try it on.
ggplot(df, aes(x,y)) + geom_point(size = 2)

我该怎么做？

Answer 1

您正在寻找annotation_raster和readPNG

mypngfile <- download.file('http://api.altmetric.com/donut/502878_64x64.png', destfile = 'mypng.png', mode = 'wb')
library(png)
mypng <- readPNG('mypng.png')


p <- qplot(mpg, wt, data = mtcars) + theme_bw()
p + annotation_raster(mypng, ymin = 4.5,ymax= 5,xmin = 30,xmax = 35) + 
    geom_point()

这些新功能（以及更多示例）描述为here

Answer 2

正确的解决方案是：

# This was one of my issues, reading a png from the web
my_image <-  readPNG(getURLContent('http://path.to/image.png'))
p1 + annotation_raster(my_image, ymin = 4,ymax= 5,xmin = 30,xmax = 40)

Answer 3

只需添加来自极好的Magick包的更新，它甚至可以将GIF覆盖在ggplot图像上：

           bundles.Add(new StyleBundle("~/Content/css").Include(
                      "~/Content/bootstrap.css",
                      "~/Content/font-awesome.css",
                      "~/Content/nprogress.css",
                      "~/Content/iCheck/flat/green.css",
                      "~/Content/daterangepicker.css",
                      "~/Content/bootstrap-dialog.css",
                      "~/Content/Tooltipster/css/tooltipster.css",
                      "~/Content/custom.css"));

            bundles.Add(new ScriptBundle("~/bundles/gentelella").Include(
                        "~/Scripts/fastclick.js",
                        "~/Scripts/nprogress.js",
                        "~/Scripts/jquery.icheck.js",
                        "~/Scripts/date.js",
                        "~/Scripts/moment-with-locales.js",
                        "~/Scripts/daterangepicker.js",
                        "~/Scripts/validator/validator.js",
                        "~/Scripts/bootstrap-dialog.js",
                        "~/Scripts/jquery.tooltipster.js",
                        "~/Scripts/custom.js"));