更改 R 中 ggplot2 中栅格的颜色类别和比例

Question

我想修改我的调色板操作的颜色，以扩大黄色区域，以便我的图中的极值更加突出。我不知道如何改变它，但下面有一个例子。

加载库：

library(tidyterra)
library(ggplot2)
library(terra)
library(dplyr)

创建一个示例数据框，然后将其转换为栅格：

df <- data.frame( x = rep( 0:1, each = 2 ),
                  y = rep( 0:1,  2),
                  l = rnorm( 4 ))

df_raster <- rasterFromXYZ(df) %>% terra::rast()

And below, I try to use breaks = to break the color palette into different categories. Unfortunately, it seems to do nothing. I want to expand the yellow region in the middle of the bl_yl_rd, and would be happy to designate certain numbers to indicate where along the values of my raster it should transition colors. Is there a way to do this, or a different function other than scale_fill_whitebox that will do a better job of this?

ggplot() + geom_spatraster(数据 = df_raster) + scale_fill_whitebox_c（调色板=“bl_yl_rd”，休息= 2）

Answer 1

使用

breaks

作为向量，例如：

df <- data.frame( x = rep( 0:1, each = 2 ),
                  y = rep( 0:1,  2),
                  l = rnorm( 4 ))

df_raster <- terra::rast(df)

ggplot2::ggplot() + 
  tidyterra::geom_spatraster(data = df_raster) +
  tidyterra::scale_fill_whitebox_b(palette = "bl_yl_rd", breaks = c(0, 1))

^{创建于 2024-02-29，使用 reprex v2.1.0}