如何在ggplot2中绘制具有特定颜色的连续色轮

Question

我正在尝试在特定位置绘制具有 12 种特定颜色的渐变色轮。目的是为认知科学实验重现带有颜色而不是数字的表盘环境。所需的输出应该如下所示：

我能够创建离散色轮，如下所示：

library(ggplot2)

data <- data.frame(
  number=c(1:12),
  count=rep(10, 12),
  cs=c('#FE2712', '#FC600A', '#FB9902', '#FCCC1A', '#FEFE33', '#B2D732', 
       '#66B032', '#347C98', '#0247FE', '#4424D6', '#8601AF', '#C21460'))

data$fraction = data$count / sum(data$count)

# Compute cumulative percentages (top of each rectangle)
data$ymax = cumsum(data$fraction)

# Compute bottom of each rectangle
data$ymin = c(0, head(data$ymax, n=-1))

# 15 degrees in radians
deg15 <- 0.26179999

(basicwheel <-
  ggplot(data, aes(ymax=ymax, ymin=ymin, xmax=1, xmin=0, fill= as.factor(number), color='black')) +
  geom_rect(inherit.aes = T) +
  coord_polar(theta="y", start=deg15) +
  xlim(c(0, 1))+
  scale_color_manual(values = 'black')+
  scale_fill_manual(values= cs)+
  theme_void()+
  theme(legend.position = '')
)

然后，我尝试通过保持每个切片中心的纯色值来调整该图，同时添加发散渐变，一侧渐变为前一个切片的纯色，另一侧渐变为下一个切片的颜色侧面。

我创建了一个矩阵，其中包含与自己的、下一个和上一个切片的颜色相关联的颜色值。

colmat <- data.frame(number = numeric(length(unique(data$number))),
                     ymax = numeric(length(unique(data$number))),
                     ymin = numeric(length(unique(data$number))),
                     previous_color = numeric(length(unique(data$number))),
                     next_color = numeric(length(unique(data$number))),
                     own_color = numeric(length(unique(data$number))))

for (i in 1:length(unique(data$number))) {
  d <- data %>% subset(as.numeric(number) == i)
  iminusone <- as.numeric(i) - 1
  iplusone <- as.numeric(i) + 1
  previousnr <- ifelse(iminusone > 0, data[which(as.numeric(data$number) == iminusone),]$number, 12)
  nxtnr <- ifelse(iplusone < 13, data[which(as.numeric(data$number) == iplusone),]$number, 1)
  colmat[i, 'number'] <- i
  
  previous_color <- colmat[i, 'previous_color'] <- data[which(as.numeric(data$number)  == previousnr),]$cs
  next_color <- colmat[i, 'next_color'] <- data[which(as.numeric(data$number) == nxtnr),]$cs
  owncolor <- colmat[i, 'own_color'] <- data[which(as.numeric(data$number) == i),]$cs
  ymax <- colmat[i, 'ymax'] <- data[which(as.numeric(data$number) == i),]$ymax
  ymin <- colmat[i, 'ymin'] <- data[which(as.numeric(data$number) == i),]$ymin
  
}

head(colmat)

但是，我仍然遗漏了一些东西，因为下面的图没有显示切片内所需的梯度。

(gwheel <-
    ggplot(colmat, aes(ymax=ymax, ymin=ymin, xmax=1, xmin=0, fill=number)) +
    geom_rect() +
    coord_polar(theta="y", start=deg15) +
    xlim(c(0, 1))+
    scale_fill_gradient2(high = colmat$previous_color, mid = colmat$own_color, low = colmat$next_color)+
    theme_void()+
    theme(legend.position = '')
)

如有任何帮助，我们将不胜感激！谢谢！

Answer 1

我认为这为您提供了所需图像的合理复制品：

library(ggplot2)

cs <- c('#FE2712', '#FC600A', '#FB9902', '#FCCC1A', '#FEFE33', 
        '#B2D732', '#66B032', '#347C98', '#0247FE', '#4424D6', 
        '#8601AF', '#C21460', '#FE2712')

vals <- seq(0, 100, 0.1)

ggplot(mapping = aes(x = 1, fill = vals, group = vals)) +
  geom_bar(aes(color = after_scale(fill)), linewidth = 0.2) +
  scale_fill_gradientn(colors = cs, guide = 'none') +
  coord_polar(theta = 'y', start = pi/2) +
  theme_void()