在探索一些数据时遇到这个问题,感觉像是意外行为,所以我想发帖。
geom_jitter
采用高度/宽度参数来表示抖动的宽度,默认值为 40%。当您添加对数刻度时,这 40% 似乎适用于原始值。但是,如果您想调整此参数,该值将在对数转换后应用。
这可以这样说明:
library(ggplot2)
library(patchwork)
set.seed(1)
dat <- data.frame(x=round(rlnorm(2000)), y=round(rlnorm(2000)))
# THESE TWO PLOTS ARE THE SAME
# with jitter
p1 <- ggplot(dat, aes(x,y)) + geom_jitter(alpha=.1) +
labs(title='regular scale, jitter with default height/width',
subtitle = '')
# with jitter, and explicit (but same as default) jitter size
p2 <- ggplot(dat, aes(x,y)) + geom_jitter(alpha=.1, height=.4, width=.4) +
labs(title='regular scale, jitter with 40% height/width',
subtitle = '<== same as that')
# THESE TWO PLOTS ARE NOT THE SAME
# with jitter and log/log scale
p3 <- ggplot(dat, aes(x,y)) + geom_jitter(alpha=.1) +
scale_x_log10() + scale_y_log10() +
labs(title='log scale, jitter with default height/width',
subtitle = '')
# with jitter and log/log scale, and explicit (but same as default) jitter size
p4 <- ggplot(dat, aes(x,y)) + geom_jitter(alpha=.1, height=.4, width=.4) +
scale_x_log10() + scale_y_log10() +
labs(title='log scale, jitter with 40% height/width',
subtitle = '<== NOT the same as that')
(p1 + p2) / (p3 + p4)
这是预期的行为吗?
如果我想调整基础值而不是对数转换值的抖动宽度怎么办?
最佳答案
这是一个不错的收获!我想这是一个文档问题——还不够清楚。抖动不是 40%,它是数据分辨率的 40%。
在 ggplot2:::PositionJitter$setup_params
中可以看到应用了 ggplot2:::resolution
函数,其结果乘以 0.4
:
list(width = self$width %||% (resolution(data$x, zero = FALSE) *
0.4), height = self$height %||% (resolution(data$y, zero = FALSE) *
0.4), seed = self$seed)
所以你需要做的是在将值传递给 width
/height
:
ggplot2:::resolution
geom_jitter(
width = ggplot2:::resolution(log10(dat$x), FALSE) * 0.4,
height = ggplot2:::resolution(log10(dat$y), FALSE) * 0.4,
)
所有代码:
ggplot(dat, aes(x, y)) +
geom_jitter(
width = ggplot2:::resolution(log10(dat$x), FALSE) * 0.4,
height = ggplot2:::resolution(log10(dat$y), FALSE) * 0.4,
) +
scale_x_log10() +
scale_y_log10() +
labs(title = 'Scale when resolution is applied')
关于r - geom_jitter 的高度/宽度参数与对数刻度交互,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/56013149/