如何在图上反转y轴

时间:2012-04-28 04:26:57

标签: r plot

我想知道如何在R中绘制一个图,其中y轴被反转,使得绘制的数据出现在笛卡尔平面的第四象限(IV)中,而不是第一个(I)象限。

作为参考,我想要制作的情节看起来非常类似于以下情况(source):

a plot with inverted y-axis

我在网上发现了许多关于在y轴上反转编号的问题,但这些问题仍然在第一象限中绘制数据。任何人都可以建议我如何制作类似于上图所示的情节?

3 个答案:

答案 0 :(得分:10)

根据@timriffe和@joran的评论提供一个得出的答案......

将此功能用于this answer的次要日志:

minor.ticks.axis <- function(ax,n,t.ratio=0.5,mn,mx,...){

  lims <- par("usr")
  if(ax %in%c(1,3)) lims <- lims[1:2] else lims[3:4]

  major.ticks <- pretty(lims,n=5)
  if(missing(mn)) mn <- min(major.ticks)
  if(missing(mx)) mx <- max(major.ticks)

  major.ticks <- major.ticks[major.ticks >= mn & major.ticks <= mx]

  labels <- sapply(major.ticks,function(i)
    as.expression(bquote(10^ .(i)))
                   )
  axis(ax,at=major.ticks,labels=labels,...)

  n <- n+2
  minors <- log10(pretty(10^major.ticks[1:2],n))-major.ticks[1]
  minors <- minors[-c(1,n)]

  minor.ticks = c(outer(minors,major.ticks,`+`))
  minor.ticks <- minor.ticks[minor.ticks > mn & minor.ticks < mx]


  axis(ax,at=minor.ticks,tcl=par("tcl")*t.ratio,labels=FALSE)

}

制作一些可重复的示例数据:

x <- 1:8
y <- 10^(sort(runif(8, 1, 10), decreasing = TRUE))

没有轴的情节:

plot(x, log10(y), # function to plot
xlab="",          # suppress x labels
type = 'l',       # specify line graph
xlim = c(min(x), (max(x)*1.3)),  # extend axis limits to give space for text annotation
ylim = c(0, max(log10(y))),      # ditto
axes = FALSE)    # suppress both axes

添加花式日志轴并向上翻转刻度标签(感谢@joran!):

minor.ticks.axis(2, 9, mn=0, mx=10, las=1)

在顶部添加x轴:

axis(3)

添加x轴标签(感谢提示@WojciechSobala)

mtext("x", side = 3, line = 2)

并在行尾添加注释

text(max(x), min(log10(y)), "Example", pos = 1)

结果如下:

enter image description here

答案 1 :(得分:4)

回答标题中的问题,反转轴的最佳/最简单的方法是翻转set_namespace变量:

limit

standard plot

> plot(1:10, xlim=c(1,10));

plot with inverted X axis

> plot(1:10, xlim=c(10,1));

plot with inverted Y axis

这样做意味着您不需要处理与图像坐标不同的轴。

这可以与&#39; xaxt =&#34; n&#34;&#39;参数和另一个> plot(1:10, ylim=c(10,1)); 命令将轴放在另一侧:

axis

Inverted graph with X axis on top

答案 2 :(得分:0)

现在很容易使用scale_y_reverse反转y轴,并在position = "top"

中为x轴指定ggplot2

示例

library(ggplot2)
library(scales)

set.seed(99)
Date <- seq(from = as.Date("2017-12-01"), to = as.Date("2017-12-15"),
             by = "days")
Flux <- runif(length(Date), 1, 10000)
Flux_df <- data.frame(Date, Flux)

p1 <- ggplot(Flux_df, aes(Date, Flux)) +
  geom_col() +
  xlab("") +
  scale_x_date(position = "top", breaks = pretty_breaks(), expand = c(0, 0)) +
  scale_y_reverse(expand = expand_scale(mult = c(0.2, 0))) +
  theme_bw(base_size = 16) +
  theme(panel.border = element_blank(),
        panel.grid.major.x = element_blank(),
        panel.grid.minor = element_blank(),
        axis.line = element_line()) +
  theme(legend.position = "none")
p1

enter image description here

如果我们同时需要对数轴和反向轴,我们需要一个建议的解决方法here,因为ggplot2没有该选项atm

reverselog_trans <- function(base = exp(1)) { 
  trans <- function(x) -log(x, base) 
  inv <- function(x) base^(-x) 
  scales::trans_new(paste0("reverselog-", format(base)), trans, inv, 
                    scales::log_breaks(base = base), domain = c(1e-100, Inf)) 
}


p1 + scale_y_continuous(trans = reverselog_trans(10),
                        breaks = scales::trans_breaks("log10", function(x) 10^x),
                        labels = scales::trans_format("log10", scales::math_format(10^.x)),
                        expand = expand_scale(mult = c(0.2, 0))) +
  annotation_logticks()

enter image description here