线周围的缓冲区ggplot2

Question

我想要一个图表，它作为一年中的一天的函数，在 x 和 y 轴上从 0 -> 100% 前进（其中每个轴都是一个单独的指标）。根据数据相对于一年中某一天的位置，我想说明这是好是坏。很简单，我可以这样展示：

因此，上图显示我们处于良好状态，因为“尖端”（最暗的最大点）已超过 50% 标记（假设我们全年为 50%）。但我想在水平线和垂直线周围添加渐变线以显示更多细微差别。这是对这些区域的解释（第一张图是解释……第二张是我想在 ggplot 中显示的方式……完全填充区域。

这是我在 ggplot 中的进展：

我遇到的问题：

1. 由于某种原因，垂直渐变不接受 alpha 参数
2. 我不能分配两个不同的渐变，一旦我定义了渐变，它就会应用于垂直和水平的渐变。
3. 这看起来很糟糕。我应该遵循更好的方法吗？

问题 1-2 是否可以解决？如果有人有更好的方法不使用geom_line，请随时提出建议。

编辑：随着线条移动，渐变也会移动，因此静态背景在这里不起作用。

代码如下：

dff <- data.frame(x = 1:60+(runif(n = 60,-2,2)),
                  y = 1:60+(runif(n = 60,-2,2)),
                  z = 1:60)

dfgrad <- data.frame(static = c(rep(50,1000)), line = seq(0,100,length.out=100))

## To see the gradientlines thinner, change the size on the geom_line  to like 200

ggplot(dff,aes(x,y)) +
  geom_line(data = dfgrad, aes(x=static, y=line, color=line),size=1000,alpha=0.5) +
  geom_line(data = dfgrad, aes(x=line, y=static, color=line),size=1000,alpha=0.5) +
  scale_colour_gradientn( colours = c( "yellow", "darkgreen","darkred"),
                          breaks  = c( 0, 3, 100),
                          limits  = c( 0,100)) +
  geom_hline(yintercept = 50, linetype="dashed") +
  geom_vline(xintercept = 50, linetype="dashed") +
  geom_point(aes(alpha=dff$z,size= (dff$z))) +
  theme(legend.position="none") +
  scale_x_continuous(expand = c(0, 0)) + scale_y_continuous(expand = c(0, 0))

最终编辑：提交的答案是正确的，但是为了根据“今天”行更改渐变，我不得不再弄乱一点......所以我将它粘贴在这里以防它对任何人有用：

g1 <- colorRampPalette(c("darkgreen", "darkgreen","red"))(20) %>%
  alpha(0.3) %>% matrix(ncol=1) %>%  # up and down gradient
  rasterGrob(width = 1, height = 1)  # full-size (control it by ggplot2)

g2 <- colorRampPalette(c("yellow", "darkgreen","red"))(20) %>% 
  alpha(0.3) %>% matrix(nrow=1) %>%  # left and right gradient
  rasterGrob(width = 1, height = 1)

timeOfYear <- 5
maxx <- max(timeOfYear,(100-timeOfYear))

ggplot(dff,aes(x,y)) +
  annotation_custom(g1, xmin = timeOfYear-maxx, xmax = timeOfYear+maxx, ymin = timeOfYear-maxx, ymax = timeOfYear+maxx) +
  annotation_custom(g2, xmin = timeOfYear-maxx, xmax = timeOfYear+maxx, ymin = timeOfYear-maxx, ymax = timeOfYear+maxx) +
  # annotation_custom(g1, xmin = 35, xmax = 65, ymin = -3, ymax = 100) +
  # annotation_custom(g2, xmin = -3, xmax = 100, ymin = 35, ymax = 65) +
  geom_hline(yintercept = timeOfYear, linetype="dashed") +
  geom_vline(xintercept = timeOfYear, linetype="dashed") +
  geom_point(aes(alpha=dff$z,size= (dff$z))) +
  theme(legend.position="none") +
  coord_cartesian(xlim = c(0, 100), ylim = c(0, 100), expand = F)

Answer 1

如果我是你，我会使用 grid 包制作矩形，然后使用 annotation_custom() 将它们放在图表上。 （你的问题1是因为覆盖，试试alpha=0.05）

这是我的例子：

library(ggplot2); library(grid); library(dplyr)

g1 <- colorRampPalette(c("yellow", "darkgreen","darkred"))(20) %>%
  alpha(0.5) %>% matrix(ncol = 1) %>%   # up and down gradient
  rasterGrob(width = 1, height = 1)     # full-size (control it by ggplot2)

g2 <- colorRampPalette(c("cyan", "darkgreen","darkblue"))(20) %>% 
  alpha(0.5) %>% matrix(nrow = 1) %>%   # left and right gradient
  rasterGrob(width = 1, height = 1)

ggplot(dff,aes(x,y)) +
  annotation_custom(g1, xmin = 35, xmax = 65, ymin = -3, ymax = 100) + 
  annotation_custom(g2, xmin = -3, xmax = 100, ymin = 35, ymax = 65) + 
  geom_hline(yintercept = 50, linetype="dashed") +
  geom_vline(xintercept = 50, linetype="dashed") +
  geom_point(aes(alpha=dff$z,size= (dff$z))) +
  theme(legend.position="none") +
  coord_cartesian(xlim = c(-3, 100), ylim = c(-3, 100), expand = F)

[已编辑]

这是我为每个 timeOfYear 保持相同程度梯度的方法（我参考了@Amit Kohli 的代码）（左图是概念）；

 # I added both limits colors as outside colors 
 # to avoid that graph becomes almost green when timeOfYear is about 50.
g1.2 <- c(rep("yellow", 5), colorRampPalette(c("yellow", "darkgreen","red"))(20), rep("red", 5)) %>%
  rev() %>% alpha(0.3) %>% matrix(ncol=1) %>% rasterGrob(width = 1, height = 1)

g2.2 <- c(rep("yellow", 5), colorRampPalette(c("yellow", "darkgreen","red"))(20), rep("red", 5)) %>%
  alpha(0.3) %>% matrix(nrow=1) %>% rasterGrob(width = 1, height = 1)

timeOfYear <- 5

ggplot(dff, aes(x, y)) +
  annotation_custom(g1.2, timeOfYear - 100, timeOfYear + 100, timeOfYear - 100, timeOfYear + 100) +
  annotation_custom(g2.2, timeOfYear - 100, timeOfYear + 100, timeOfYear - 100, timeOfYear + 100) + 
  geom_hline(yintercept = timeOfYear, linetype="dashed") +
  geom_vline(xintercept = timeOfYear, linetype="dashed") +
  geom_point(aes(alpha=dff$z,size= (dff$z))) +
  theme(legend.position="none") +
  coord_cartesian(xlim = c(0, 100), ylim = c(0, 100), expand = F)

如果您需要，SpaDES::divergentColors() 会为您提供具有非对称范围的颜色矢量（可能某些软件包具有类似的功能）。

library(SpaDES)

timeOfYear <- 5

# ?divergentColors(start.color, end.color, min.value, max.value, mid.value = 0, mid.color = "white")    
   # It makes a vector of colors (length: max.value - min.value) 
   # and you can define mid.color's val (i.e., position)

g3 <- divergentColors("yellow", "red", 0, 100, timeOfYear, mid.color = "darkgreen") %>% 
  rev() %>% alpha(0.3) %>% matrix(ncol = 1) %>% rasterGrob(width = 1, height = 1)

g4 <- divergentColors("yellow", "red", 0, 100, timeOfYear, mid.color = "darkgreen") %>% 
  alpha(0.3) %>% matrix(nrow = 1) %>% rasterGrob(width = 1, height = 1)

ggplot(dff,aes(x,y)) +
  annotation_custom(g3, xmin = 0, xmax = 100, ymin = 0, ymax = 90) +
  annotation_custom(g4, xmin = 0, xmax = 90, ymin = 0, ymax = 100) + 
  geom_hline(yintercept = timeOfYear, linetype="dashed") +
  geom_vline(xintercept = timeOfYear, linetype="dashed") +
  geom_point(aes(alpha=dff$z,size= (dff$z))) +
  theme(legend.position="none") +
  coord_cartesian(xlim = c(0, 100), ylim = c(0, 100), expand = F)