R ggpairs改变对角线上直方图的颜色

Question

我想更改成对图上直方图条形的颜色，从而为每个变量设置不同的颜色。看来我可以通过将 'fill =' 选项更改为新颜色来更改所有对角直方图的颜色，但是当我尝试替换四种颜色的列表时，我收到错误报告：

"r: 美学必须为长度1或与数据相同(15): fill"

所以颜色似乎以某种方式链接到为直方图指定的 bin 数量而不是每个直方图的填充颜色？

为对角线上的每个直方图实现不同颜色的最佳方法是什么？

示例代码如下：

require(GGally)

# function for scatter plots with smoothed trend line
lower_plots <- function(data, mapping, ...) {
  ggplot(data = data, mapping = mapping) +
    geom_point(color = "black", shape = 1, size = 1, alpha = 1) +
    geom_smooth(method = "gam",...) 
} 

# colour palette for histograms - subsitue for fill = ?
clrs <- c("red","green","blue","orange")

# pairs plot
ggpairs(iris,1:4, 
        diag = list(continuous = wrap("barDiag", bins = 15, fill = "blue")),
        lower = list(continuous = wrap(lower_plots, color="red", se=F))) +
  theme_light(base_size = 12) +                                                                                                                 
  theme_light(base_size = 12) +                                                                                                                 
  scale_fill_manual(values = ZNS[order(ZNS$Zone), 4])  +                                                                                         
  theme(panel.grid.minor = element_blank(), panel.grid.major = element_blank()) +
  theme(plot.margin = unit(c(2.5,2.5,2.5,3.5), "lines")
  )

Answer 1

我通过在函数内部使用全局赋值找到了解决您的问题的方法。首先，由于无法在输入的一列中识别如何为直方图着色，因此我无法做到这一点，因为每一行都包含多个观察结果……我进行了一些测试并想知道，考虑到所有事实beeing 在 batches/loops 中处理，全局分配会有所帮助 - 确实如此：

require(GGally)

# function for scatter plots with smoothed trend line
lower_plots <- function(data, mapping, ...) {
    ggplot(data = data, mapping = mapping) +
        geom_point(color = "black", shape = 1, size = 1, alpha = 1) +
        geom_smooth(method = "gam",...) 
} 

# working with a trick of global assignment
diag_plots <- function(data, mapping, ...) {
    # increase counter each run globally so outside the function as well and this does the trick!
    x <<- x + 1
    ggplot(data = data, mapping = mapping) +
        # choose color by counter and send bin width argument in
        geom_histogram(fill = clrs[x], ...)
} 

# set the color and counter
clrs <- c("red","green","blue","orange")
x <- 0

# pairs plot
ggpairs(iris,1:4, 
        diag = list(continuous = wrap(diag_plots, bins = 15)),
        lower = list(continuous = wrap(lower_plots, color="red", se=FALSE))) +
        theme_light(base_size = 12) + 
        theme_light(base_size = 12) + 
        theme(panel.grid.minor = element_blank(), panel.grid.major = element_blank()) +
    theme(plot.margin = unit(c(2.5,2.5,2.5,3.5), "lines"))

R ggpairs改变对角线上直方图的颜色

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