R将图例和直接标记添加到ggplot2等高线图中

Question

我有一个栅格地图,我想使用连续比例使用ggplot2绘制,并在其上标记为等值线.

为此,我使用直接标签包,并接近得到我想要的但我无法在同一地图上同时获得图例和标记的等值线

以下代码重现了我的问题:

install.packages(c('ggplot2', 'directlabels'))
library('ggplot2')
library('directlabels')
df <- expand.grid(x=1:100, y=1:100)
df$z <- df$x * df$y

# Plot 1: this plot is fine but without contours    
p <- ggplot(aes(x=x, y=y, z=z), data = df) + 
     geom_raster(data=df, aes(fill=z)) +
     scale_fill_gradient(limits=range(df$z), high = 'white', low = 'red')
p

# Plot 2: This plot adds the isolines but no labels and it also adds a second legend for level which I don't want
p <- p + geom_contour(aes(colour = ..level..), color='gray30', na.rm=T,     show.legend=T)
p

# Plot 3: This plot has the labeled isolines but it removes the z legend that I want to show
direct.label(p, list("bottom.pieces", colour='black'))

情节1

情节2

情节3

我希望在背景中有彩色光栅,侧面是彩色图例,顶部是标记的等值线.有没有办法做到这一点？

还有一种方法可以将标签放在等值线的中间而不是底部或顶部吗？

提前致谢

巴勃罗

Answer 1

首先,解决与传说有关的问题.

library(ggplot2)
library(directlabels)

df <- expand.grid(x=1:100, y=1:100)
df$z <- df$x * df$y

p <- ggplot(aes(x=x, y=y, z=z), data = df) + 
     geom_raster(data=df, aes(fill=z), show.legend = TRUE) +
     scale_fill_gradient(limits=range(df$z), high = 'white', low = 'red') + 
     geom_contour(aes(colour = ..level..)) +
     scale_colour_gradient(guide = 'none') 

p1 = direct.label(p, list("bottom.pieces", colour='black'))
p1

定位标签的选项不多.一种可能性是angled.boxes,但fill颜色可能不太好.

p2 = direct.label(p, list("angled.boxes"))
p2

要将fill颜色更改为透明(使用此处的代码.

p3 = direct.label(p, list("far.from.others.borders", "calc.boxes", "enlarge.box", 
      box.color = NA, fill = "transparent", "draw.rects"))
p3

并将标签移离轮廓线:

p4 = direct.label(p, list("far.from.others.borders", "calc.boxes", "enlarge.box", 
      hjust = 1, vjust = 1, box.color = NA, fill = "transparent", "draw.rects"))
p4