r - 使用scale_fill_manual手动分配颜色仅适用于某些六边形尺寸

Question

我正在尝试创建一个散点图，该散点图由计数的六边形箱汇总。我希望用户能够定义色标的计数间隔。我正在使用scale_fill_manual()进行此工作。然而，奇怪的是，它仅在某些时候有效。在下面的MWE中，使用给定的种子值(如果为xbins=10)，会导致出现如下所示的问题:



但是，例如，如果使用xbins=20或40，则绘图似乎没有问题:



我的MWE如下:

library(ggplot2)
library(hexbin)
library(RColorBrewer)

set.seed(1)
xbins <- 20

x <- abs(rnorm(10000))
y <- abs(rnorm(10000))
minVal <- min(x, y)
maxVal <- max(x, y)
maxRange <- c(minVal, maxVal)
buffer <- (maxRange[2] - maxRange[1]) / (xbins / 2)
h <- hexbin(x = x, y = y, xbins = xbins, shape = 1, IDs = TRUE,
            xbnds = maxRange, ybnds = maxRange)
hexdf <- data.frame (hcell2xy(h),  hexID = h@cell, counts = h@count)
my_breaks <- c(2, 4, 6, 8, 20, 1000)
clrs <- brewer.pal(length(my_breaks) + 3, "Blues")
clrs <- clrs[3:length(clrs)]
hexdf$countColor <- cut(hexdf$counts, breaks = c(0, my_breaks, Inf), 
                        labels = rev(clrs))

ggplot(hexdf, aes(x = x, y = y, hexID = hexID, fill = countColor)) +
  scale_fill_manual(values = levels(hexdf$countColor)) +
  geom_hex(stat = "identity") + 
  geom_abline(intercept = 0, color = "red", size = 0.25) + 
  coord_fixed(xlim = c(-0.5, (maxRange[2] + buffer)), 
              ylim = c(-0.5, (maxRange[2] + buffer))) + 
  theme(aspect.ratio=1)

我的目标是调整此代码，以使绘图不会出现问题(突然某些六角形的大小和形状与其余六边形不同)，而与分配给xbins的值无关。但是，我对某些xbins值可能导致此问题的原因感到困惑。任何建议将不胜感激。

编辑:

考虑到@bdemarest和@Axeman的评论后，我正在更新示例代码。我在@Axeman建议的链接中遵循了最流行的答案，并认为当您在整数矢量上使用scale_fill_continuous()时，此方法会更有用。在这里，我正在研究因子向量上的scale_fill_manual()。结果，我仍然无法实现这个目标。谢谢你。

library(ggplot2)
library(hexbin)
library(RColorBrewer)

set.seed(1)
xbins <- 10

x <- abs(rnorm(10000))
y <- abs(rnorm(10000))
minVal <- min(x, y)
maxVal <- max(x, y)
maxRange <- c(minVal, maxVal)
buffer <- (maxRange[2] - maxRange[1]) / (xbins / 2)
bindata = data.frame(x=x,y=y,factor=as.factor(1))

h <- hexbin(bindata, xbins = xbins, IDs = TRUE, xbnds = maxRange, ybnds = maxRange)

counts <- hexTapply (h, bindata$factor, table)
counts <- t (simplify2array (counts))
counts <- melt (counts)
colnames (counts)  <- c ("factor", "ID", "counts")
counts$factor =as.factor(counts$factor)

hexdf <- data.frame (hcell2xy (h),  ID = h@cell)
hexdf <- merge (counts, hexdf)

my_breaks <- c(2, 4, 6, 8, 20, 1000)
clrs <- brewer.pal(length(my_breaks) + 3, "Blues")
clrs <- clrs[3:length(clrs)]
hexdf$countColor <- cut(hexdf$counts, breaks = c(0, my_breaks, Inf), labels = rev(clrs))

ggplot(hexdf, aes(x = x, y = y, fill = countColor)) +
  scale_fill_manual(values = levels(hexdf$countColor)) +
  geom_hex(stat = "identity") + 
  geom_abline(intercept = 0, color = "red", size = 0.25) + 
  coord_cartesian(xlim = c(-0.5, maxRange[2]+buffer), ylim = c(-0.5, maxRange[2]+ buffer)) + theme(aspect.ratio=1)

Answer 1

您可以在'geom'中定义颜色，而不是修改图比例的'scale':

ggplot(hexdf, aes(x = x, y = y)) + 
geom_hex(stat = "identity",fill =hexdf$countColor)