如何使用geom_contour_filled制作离散渐变色条? [英] How to make discrete gradient color bar with geom_contour_filled?

问题描述

我根据这样的一段代码绘制地图:

I plot a map based on a piece of code like this:

ggplot(faithfuld, aes(y=eruptions, x=waiting, z=100*density)) +
geom_contour_filled(breaks = c(-Inf,-2., -1.5, -1., -0.5, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 7, 9, 11,Inf))+
theme(plot.title = element_text(size = 10,hjust = 0.5))

这是我的情节，目前看起来像: 但是我的老板要我像这样做出传说: 或像这样: 此链接的参数( https://ggplot2.tidyverse.org/reference/theme.html)只需为图例提供较小的更改.而且我找不到任何可以实现此目的的参数，是否可以用ggplot进行?还是我必须使用其他绘图程序包?

This is my plot currently looks like: But my boss asks me to make the legend like this: or like this: Arguments from this link (https://ggplot2.tidyverse.org/reference/theme.html) just provide minor changes for the legend. And I can't find any arguments that can achieve this, is it doable with ggplot? or I have to use other plotting package?

创建离散颜色间隔宽度变化且图例级别之间没有间隔的条形图这个问题(第4个答案)提供了一种可以像我的老板所需要的那样创建颜色条的方法，但是，我使用的是geom_contour_filled(breaks = c(-Inf,-2., -1.5, -1., -0.5, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 7, 9, 11,Inf))这个参数，因此图例总是显示很多文本: 有什么解决办法吗?

Create discrete color bar with varying interval widths and no spacing between legend levels This question (answer No. 4) provides a method that can create a color bar like my boss required, however, I'm using geom_contour_filled(breaks = c(-Inf,-2., -1.5, -1., -0.5, 0, 0.5, 1, 1.5, 2, 3, 4, 5, 7, 9, 11,Inf)) this argument so the legend always appears with a lot of text: Are there any solutions?

推荐答案

我认为，这与我之前的答案已经足够不同，可以证明第二个答案是正确的.我回答了后者，完全拒绝了ggplot2 3.3.0附带的新的scale函数，现在我们可以轻松地使用它们了.我仍然保留其他解决方案，因为它可能对...非常具体的要求有所帮助.

I believe this is different enough to my previous answer to justify a second one. I answered the latter in complete denial of the new scale functions that came with ggplot2 3.3.0, and now here we go, they make it much easier. I'd still keep the other solution because it might help for ... well very specific requirements.

我们仍然需要使用metR，因为连续/离散轮廓问题仍然存在，而metR :: geom_contour_fill可以很好地解决这一问题.

We still need to use metR because the problem with the continuous/discrete contour persists, and metR::geom_contour_fill handles this well.

我正在修改scale_fill_fermenter函数，该函数在这里可以使用，因为它适用于分档刻度.我对底层的brewer_pal函数进行了略微的增强，因此，如果使用n > max(palette_colors)，它可以提供比原始啤酒酿造器更多的颜色.

I am modifying the scale_fill_fermenter function which is the good function to use here because it works with a binned scale. I have slightly enhanced the underlying brewer_pal function, so that it gives more than the original brewer colors, if n > max(palette_colors).

更新 您应该使用guide_colorsteps更改颜色栏.

update You should use guide_colorsteps to change the colorbar.

library(ggplot2)
library(metR)

mybreaks <- c(seq(-2,2,0.5), 3:5, seq(7,11,2))

ggplot(faithfuld, aes(eruptions, waiting)) +
  metR::geom_contour_fill(aes(z = 100*density)) +
  scale_fill_craftfermenter(
    breaks = mybreaks, 
    palette = "Spectral", 
    limits = c(-2,11),
    guide = guide_colorsteps(
      frame.colour = "black", 
      ticks.colour = "black", # you can also remove the ticks with NA
      barwidth=20)
  ) +
  theme(legend.position = "bottom")
#> Warning: 14 colours used, but Spectral has only 11 - New palette created based
#> on all colors of Spectral

## with uneven steps, better representing the scale 
ggplot(faithfuld, aes(eruptions, waiting)) +
  metR::geom_contour_fill(aes(z = 100*density)) +
  scale_fill_craftfermenter(
    breaks = mybreaks, 
    palette = "Spectral", 
    limits = c(-2,11),
    guide = guide_colorsteps(
      even.steps = FALSE,
      frame.colour = "black", 
      ticks.colour = "black", # you can also remove the ticks with NA
      barwidth=20, )
  ) +
  theme(legend.position = "bottom")
#> Warning: 14 colours used, but Spectral has only 11 - New palette created based
#> on all colors of Spectral

功能修改

craftbrewer_pal <- function (type = "seq", palette = 1, direction = 1) 
{
  pal <- scales:::pal_name(palette, type)
  force(direction)
  function(n) {
    n_max_palette <- RColorBrewer:::maxcolors[names(RColorBrewer:::maxcolors) == palette]
    
    if (n < 3) {
      pal <- suppressWarnings(RColorBrewer::brewer.pal(n, pal))
    } else if (n > n_max_palette){
      rlang::warn(paste(n, "colours used, but", palette, "has only",
                    n_max_palette, "- New palette created based on all colors of", 
                    palette))
      n_palette <- RColorBrewer::brewer.pal(n_max_palette, palette)
      colfunc <- grDevices::colorRampPalette(n_palette)
      pal <- colfunc(n)
    }
    else {
      pal <- RColorBrewer::brewer.pal(n, pal)
    }
    pal <- pal[seq_len(n)]
    if (direction == -1) {
      pal <- rev(pal)
    }
    pal
  }
}

scale_fill_craftfermenter <- function(..., type = "seq", palette = 1, direction = -1, na.value = "grey50", guide = "coloursteps", aesthetics = "fill") {
  type <- match.arg(type, c("seq", "div", "qual"))
  if (type == "qual") {
    warn("Using a discrete colour palette in a binned scale.\n  Consider using type = \"seq\" or type = \"div\" instead")
  }
  binned_scale(aesthetics, "fermenter", ggplot2:::binned_pal(craftbrewer_pal(type, palette, direction)), na.value = na.value, guide = guide, ...)
}

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