尝试将图像添加到极坐标图中会给出“错误:注释_自定义仅适用于笛卡尔坐标” [英] Trying to add an image to a polar plot gives "Error: annotation_custom only works with Cartesian coordinates"
问题描述
我试着按照已经给出的答案将图片添加到图中,但在使用 coord_polar()
#install时,它们不起作用.packages(RCurl,dependencies = TRUE)
library(RCurl)
myurl< - http://vignette2.wikia.nocookie.net/micronations/images/5/50/German_flag。 png
#install.packages(png,dependencies = TRUE)
library(png)
img< - readPNG(getURLContent(myurl))
#install.packages(ggplot2,dependencies = TRUE)
library(ggplot2)
ger < - grid :: rasterGrob(img,interpolate = TRUE)
##工作,将图像添加到图
ggplot(mtcars,aes(x = mpg,y = cyl))+ geom_line()+ annotation_custom(ger,10,15,5)
##不起作用
ggplot(mtcars,aes(x = mpg,y = cyl))+ geom_line()+ annotation_custom(ger)+ coord_polar()
>错误:annotation_custom仅适用于笛卡尔坐标
理想情况下,我希望能够定位标志图像在极坐标图的中心,沿着y轴的另一个图像。
是否有添加图像的方法?它可以是原样的,不需要转换。
我使用 ggplot2
版本2.0
继 cowplot简介,您可以使用 draw_grob
函数根据需要叠加图像。它需要调整位置,因为位置会根据图的尺寸而变化,但可能会有所不同。
示例:
#install.packages(RCurl,dependencies = TRUE)
library(RCurl)
myurl< - http://vignette2.wikia .nocookie.net / micronations / images / 5/50 / German_flag.png
#install.packages(png,dependencies = TRUE)
library(png)
img< - readPNG(getURLContent(myurl))
#install.packages(ggplot2,dependencies = TRUE)
library(ggplot2)
ger< ; - grid :: rasterGrob(img,interpolate = TRUE)
$ bg < - ggplot(mtcars,aes(x = mpg,y = cyl))+ geom_line()+ coord_polar()
#install.packages(cowplot,依赖关系= TRUE)
库(cowplot)
h < - ggdraw(g)
##调整以适合您的绘图
h + draw_grob(ger,0.4,0.48,0.07,0.07)
I've tried to follow the answer's given already for adding images to plots, but they do not work when using coord_polar()
# install.packages("RCurl", dependencies = TRUE)
library(RCurl)
myurl <- "http://vignette2.wikia.nocookie.net/micronations/images/5/50/German_flag.png"
# install.packages("png", dependencies = TRUE)
library(png)
img <- readPNG(getURLContent(myurl))
# install.packages("ggplot2", dependencies = TRUE)
library(ggplot2)
ger <- grid::rasterGrob(img, interpolate=TRUE)
## works, adds the image to the plot
ggplot(mtcars, aes(x=mpg, y= cyl)) + geom_line() + annotation_custom(ger, 10, 15, 5)
## doesn't work
ggplot(mtcars, aes(x=mpg, y= cyl)) + geom_line() + annotation_custom(ger) + coord_polar()
> Error: annotation_custom only works with Cartesian coordinates
Ideally I'd like to be able to position the flag image within the center of the polar plot, and another image along the y-axis.
Is there anyway to add the image? It can be as-is, no transformation required.
I'm using ggplot2
version 2.0
Gregor's suggestion for using the cowplot
library has got me there.
Following the introduction to cowplot you can use the draw_grob
function to overlay images as you like. It takes a bit of tweaking as the position changes depending on the dimensions of the plot, but its possible.
Example:
# install.packages("RCurl", dependencies = TRUE)
library(RCurl)
myurl <- "http://vignette2.wikia.nocookie.net/micronations/images/5/50/German_flag.png"
# install.packages("png", dependencies = TRUE)
library(png)
img <- readPNG(getURLContent(myurl))
# install.packages("ggplot2", dependencies = TRUE)
library(ggplot2)
ger <- grid::rasterGrob(img, interpolate=TRUE)
g <- ggplot(mtcars, aes(x=mpg, y= cyl)) + geom_line() + coord_polar()
# install.packages("cowplot", dependencies = TRUE)
library(cowplot)
h <- ggdraw(g)
## tweak this to fit your plot
h + draw_grob(ger, 0.4, 0.48, 0.07, 0.07)
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