Levelplot颜色键-范围和极限 [英] Levelplot color key - range and extremes
问题描述
在R中是否可以像下面那样创建一个颜色键? (这来自软件Grid Analysis and Display System-Grads).
Is it possible in R to create a color key like the one below? (this one comes from the software Grid Analysis and Display System - Grads).
我无法在R中复制两个功能:
There are two features that I can't reproduce in R:
- 序列是非线性的,但是显示为
- 大于200的值为灰色/小于0的值为白色
我正在使用rastervis的levelplot,它使用点阵levelplot绘制栅格:
I'm using levelplot from rastervis that plots rasters using the lattice levelplot:
require(raster)
require(rasterVis)
set.seed(200)
X = seq(-40,0,by=1)
Y = seq(-60,-40,by=1)
grid = expand.grid(list(X=X,Y=Y))
Z = rnorm(nrow(grid),mean=10,sd=100)
data = data.frame(grid,Z)
r = rasterFromXYZ(data)
mapTheme <- rasterTheme(region=c('#EEF7FA','#D6F8F7',"#BEDAFF",'#5DA4FF',"#0000FF","#D4F9E2","#00FF7F","#008000","#FFFF00","#FFD27F", "#FFB732" ,"#EE7600",
"#D53E4F","#FF6A6A"))
my.at = c(0,1,5,10,15,20,25,30,40,50,75,100,150,200)
myColorkey <- list(at=my.at,
space="bottom",
labels=list(at=my.at))
p=levelplot(r, par.settings=mapTheme,at = my.at, colorkey=myColorkey,margin=F)
print(p)
结果:
如您所见,小于0和大于200的值都是白色,我不知道如何设置大于或小于特定值的值以显示为特定颜色. Morover,尽管间隔不相同,我如何才能使彩色键中连续的粗线标记之间的间隔具有相同的大小?
As you can see, both values smaller than 0 and bigger than 200 are white, I've no idea how to set values bigger than or smaller than a certain value to appear as a specific color. Morover, how can I make the space between consecutive thick marks in the color key to have the same size although the intervals are not the same?
推荐答案
这是解决非线性序列大小相等的间隔的解决方法:
This is a workaround for equally sized intervals for non linear sequences:
library(raster)
library(rasterVis)
set.seed(200)
X = seq(-40,0,by=1)
Y = seq(-60,-40,by=1)
grid = expand.grid(list(X=X,Y=Y))
Z = rnorm(nrow(grid),mean=10,sd=100)
data = data.frame(grid,Z)
r = rasterFromXYZ(data)
mapTheme <- rasterTheme(region=c('#EEF7FA','#D6F8F7',"#BEDAFF",'#5DA4FF',"#0000FF","#D4F9E2","#00FF7F",
"#008000","#FFFF00","#FFD27F", "#FFB732" ,"#EE7600", "#D53E4F","#FF6A6A"))
my.at=c(0,1,5,10,15,20,25,30,40,50,75,100,150,200)
my.brks=seq(0, 200, by=15)
myColorkey <- list(at=my.brks, labels=list(at=my.brks, labels=my.at), space="bottom")
p=levelplot(r, par.settings=mapTheme, at=my.at, colorkey=myColorkey, margin=F)
print(p)
对于小于0且大于200的值,这可能是一种解决方案:
This could be a solution for values smaller 0 and greater than 200:
library(raster)
library(rasterVis)
set.seed(200)
X = seq(-40,0,by=1)
Y = seq(-60,-40,by=1)
grid = expand.grid(list(X=X,Y=Y))
Z = rnorm(nrow(grid),mean=10,sd=100)
data = data.frame(grid,Z)
r = rasterFromXYZ(data)
mapTheme <- rasterTheme(region=c('white','#EEF7FA','#D6F8F7',"#BEDAFF",'#5DA4FF',"#0000FF","#D4F9E2","#00FF7F",
"#008000","#FFFF00","#FFD27F", "#FFB732" ,"#EE7600", "#D53E4F","#FF6A6A", "gray"))
max(values(r))
min(values(r))
my.at=c(min(values(r)), 0,1,5,10,15,20,25,30,40,50,75,100,150,200, max(values(r)))
my.brks=seq(0, 200, by=13)
myColorkey <- list(at=my.brks, labels=list(at=my.brks, labels=c(-276,0,1,5,10,15,20,25,30,40,50,75,100,150,200, 388)), space="bottom")
p=levelplot(r, par.settings=mapTheme, at=my.at, colorkey=myColorkey, margin=F)
print(p)
您的颜色没有从浅色变为深色.您可以使用RColorBrewer软件包来解决此问题.
Your colors are not progressing from light to dark. You can use the RColorBrewer package to fix this.
library(RColorBrewer)
reds = brewer.pal(5, "YlOrRd")
greens = brewer.pal(3, "Greens")
blues = brewer.pal(5, "Blues")
mapTheme <- rasterTheme(region=c('white', blues, greens, reds, "gray"))
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