R更新后ggplot用trans_new()实现x轴立方根缩放报错求助

报错原因 #

1. 自定义变换函数的缺陷：原代码中直接用x^(1/3)计算立方根，在R中负数的1/3次方会返回复数（例如(-1)^(1/3)结果为复数），而非实数，这会导致变换后产生NA或非有限值，触发zero_range函数的判断错误（需要TRUE/FALSE值却得到缺失值）。
2. 分面自由缩放的影响：facet_wrap(~site + SYear, scales = "free")会让每个面板独立计算x轴范围，若某面板的x值范围经过错误变换后出现异常，会进一步触发该报错。

解决方案：修复自定义立方根变换函数 #

修改变换函数，确保对负数返回实数立方根，同时避免复数生成：

# 修复后的立方根变换函数
transform_cuberoot = function(){
  trans_new('cuberoot',
            transform = function(x) sign(x) * abs(x)^(1/3),  # 处理负数，返回实数
            inverse = function(x) x^3,
            breaks = c(0, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0),
            domain = c(-Inf, Inf))
} 

使用原代码的scale_x_continuous调用这个修复后的函数即可，无需更换为coord_trans。这样既保留所有绘图元素（包括y=0的虚线、坐标轴），也不会产生无穷值警告。

关于coord_trans的问题说明 #

使用coord_trans(x = transform_cuberoot())出现元素丢失和警告，是因为该函数会对整个坐标系进行变换，包括geom_hline等元素的坐标。当变换产生无穷值时，这些元素会被挤出可视区域，同时触发"Transformation introduced infinite values"警告。因此优先使用scale_x_continuous的trans参数，仅对轴刻度和数据映射进行变换，而非整个坐标系。

完整可运行代码示例 #

结合你的数据和修复后的变换函数，完整代码如下：

library(ggplot2)
library(scales)

# 修复后的立方根变换
transform_cuberoot = function(){
  trans_new('cuberoot',
            transform = function(x) sign(x) * abs(x)^(1/3),
            inverse = function(x) x^3,
            breaks = c(0, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0),
            domain = c(-Inf, Inf))
} 

# 示例数据
df <- structure(list(site = c("US", "US", "US", "US", "US", "US"), 
                     Transect = c(1L, 1L, 1L, 1L, 1L, 1L), Plot = c(100L, 103L, 
                                                                     106L, 109L, 112L, 115L), Year = c(2020L, 2020L, 2020L, 2020L, 
                                                                                                       2020L, 2020L), SYear = c("2020-2021", "2020-2021", "2020-2021", 
                                                                                                                               "2020-2021", "2020-2021", "2020-2021"), E.Delta = c(-0.0380000000000109, 
                                                                                                                                                                                     -0.0930000000000746, -0.0950000000000273, -0.0709999999999127, 
                                                                                                                                                                                     -0.104000000000042, -0.0989999999999327), I = c(1, 1, 1, 
                                                                                                                                                                                                                                       1, 1, 1), AllRtedPctCov = c(0, 0, 0, 0, 0, 0), NoRtedVeg = c(1, 
                                                                                                                                                                                                                                                                                                       1, 1, 1, 1, 1), PerCov.15 = structure(c(1L, 1L, 1L, 1L, 1L, 
                                                                                                                                                                                                                                                                                                                                               1L), levels = c("0", "1"), class = "factor")), row.names = c(NA, 
                                                                                                                                                                                                                                                                                                                                                                                                           6L), class = "data.frame")

# 绘图代码
ggplot(df, aes(x = I, y = E.Delta, color = PerCov.15)) +
  geom_point(size = 1.5) +
  facet_wrap(~site + SYear, scales = "free") +
  theme_classic() +
  geom_hline(yintercept = 0, linetype = "dashed", color = "red") +
  labs(x = "Inundation-Duration", y = "Change in Elevation", color =" Percent Rooted Cover") +
  scale_colour_brewer(labels= c("<15%", ">15%"), type = "qual", palette = 3) +
  theme(axis.title.x = element_text(size = 16, vjust = -2),
        axis.title.y = element_text(size = 16, vjust = 5),
        legend.title = element_text(size = 16),
        legend.text = element_text(size = 16),
        strip.background = element_blank(),
        strip.text = element_text(size = 18),
        axis.text = element_text(size = 14),
        plot.margin = unit(c(2,2,2,2), "cm"),
        panel.spacing = unit(3, "lines"))+
  scale_x_continuous(trans = transform_cuberoot(), 
                     breaks = c(0, 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0),
                     labels=c(0, 0.01, 0.1, " ", 0.3, " ", " ", 0.6, " ", " ", " ", 1.0)) 

内容的提问来源于stack exchange，提问作者Cat