r - 如何生成一个 (Y) 轴的 ggplot Log10 比例图？

Question

我有一组数据想要制作对数刻度图，我希望图形的 Y 轴为 log10 刻度，X 轴为正常时间序列。

我已经尝试了在互联网上和这个网站上找到的各种图表的各种方法，但它们似乎都没有按照我想要的方式工作，要么给出一个空图表，要么不显示轴(只是label)，或者甚至给出一个空的 png 文件。

library(ggplot2)
library(MASS)
library(scales)

# assume everything happens in GMT timezone
Sys.setenv( TZ = "GMT" )
# replicating the data: a measurement result sampled at 1 sec interval
t <- seq(start, end, by = "1 sec")
Time24 <- trimws(strftime(t, format = "%k:%M:%OS", tz="GMT"))
Date <- strftime(t, format = "%d/%m/%Y", tz="GMT")
head(Time24)
head(Date)
d <- data.frame(Date, Time24)
d$temp <- rnorm(length(d$Date),mean=25,sd=5)
head(d)
# the resulting data is as follows
#        Date  Time24     temp
#1 22/05/2019 0:00:00 22.67185
#2 22/05/2019 0:00:01 19.91123
#3 22/05/2019 0:00:02 19.57393
#4 22/05/2019 0:00:03 15.37280
#5 22/05/2019 0:00:04 31.76683
#6 22/05/2019 0:00:05 26.75153


# combining the the date and the time column of the data
t <- as.POSIXct(paste(d$Date,d$Time24,sep=" "), format = "%d/%m/%Y %H:%M:%OS", tz="GMT")

# Log Scale Method 1
png(filename = "Method 1.png", width = 800, height = 600, units = "px", pointsize = 22 )
ggplot(df,aes(x=t,y=Temp)) + geom_line() +
  scale_x_datetime(name="Time",date_breaks = "2 hour",
                   date_labels = "%H:%M\n%d-%b") +

  # Log Scale transformation code 1
  scale_y_continuous(trans = "log10") +

  labs(title="Method 1", y="Temperature (C)") +
  theme(plot.title = element_text(hjust = 0.5, size = 20),
        axis.title.x = element_text(size = 18),
        axis.title.y = element_text(size = 18),
        axis.text.x = element_text(size=14),
        axis.text.y = element_text(size=14))

# Log Scale Method 2
png(filename = "Method 2.png", width = 800, height = 600, units = "px", pointsize = 22 )

# Log Scale transformation code 2
ggplot(df,aes(x=t,y=Temp), log10="y") + geom_line() +

  scale_x_datetime(name="Time",date_breaks = "2 hour",
                   date_labels = "%H:%M\n%d-%b") +
  labs(title="Method 2", y="Temperature (C)") +
  theme(plot.title = element_text(hjust = 0.5, size = 20),
        axis.title.x = element_text(size = 18),
        axis.title.y = element_text(size = 18),
        axis.text.x = element_text(size=14),
        axis.text.y = element_text(size=14))

# Log Scale Method 3
png(filename = "Method 3.png", width = 800, height = 600, units = "px", pointsize = 22 )
ggplot(df,aes(x=t,y=Temp)) + geom_line() +
  scale_x_datetime(name="Time",date_breaks = "2 hour",
                   date_labels = "%H:%M\n%d-%b") +

  # Log Scale tranfsormation code 3
  scale_y_log10(breaks = trans_breaks("log10", function(x) 10^x),
                labels = trans_format("log10", math_format(10^.x))) +

  labs(title="Method 3", y="Temperature (C)") +
  theme(plot.title = element_text(hjust = 0.5, size = 20),
        axis.title.x = element_text(size = 18),
        axis.title.y = element_text(size = 18),
        axis.text.x = element_text(size=14),
        axis.text.y = element_text(size=14))

# Log Scale Method 4
png(filename = "Methpd 4.png", width = 800, height = 600, units = "px", pointsize = 22 )
ggplot(df,aes(x=t,y=Temp)) + geom_line() +
  scale_x_datetime(name="Time",date_breaks = "2 hour",
                   date_labels = "%H:%M\n%d-%b") +

  # Log Scale transformation code 4
  scale_y_continuous(formatter='log10')

  labs(title="Method 4", y="Temperature (C)") +
  theme(plot.title = element_text(hjust = 0.5, size = 20),
        axis.title.x = element_text(size = 18),
        axis.title.y = element_text(size = 18),
        axis.text.x = element_text(size=14),
        axis.text.y = element_text(size=14))



quit()

我希望 Y 轴显示 log10 的缩放比例和刻度标签，如下所示:

但是我通过尝试过的各种方法产生了这些结果:

代码的第一部分只是我的数据集的占位符，我知道我无法以 csv 的形式在此处发布，而且我不知道如何发布我的代码并使其成为完美的可重现结果，我对 R 非常陌生，尤其是 ggplot2，对于任何错误和缺点，我深表歉意，提前致谢。

Answer 1

tl;dr您的数据范围(大约 23-27)太小，无法有效使用对数刻度。您可以手动设置中断(请参阅下面的方法#2)，在这种情况下，看起来 ggplot 不尊重您对对数刻度轴的请求，而是考虑线性刻度和对数刻度之间的差异在此数据范围内几乎无法区分。

设置数据:

set.seed(101)
dd <- data.frame(x=seq.Date(as.Date("2019-01-01"),as.Date("2019-01-31"), by="1 day"), 
   y = runif(31,min=23,max=27))
dd2 <- transform(dd,y=c(25,runif(29,min=23,max=27),27000))

方法一:无轴刻度，同上

library(ggplot2)
(gg1 <- ggplot(dd,aes(x,y))+geom_point()+scale_x_date()+scale_y_log10())
gg1 %+% dd2

方法2:手动指定轴中断(与方法2基本相同)

(gg2 <- ggplot(dd,aes(x,y))+geom_point()+scale_x_date()+scale_y_log10(breaks=23:27))
gg2 %+% dd2 + scale_y_log10(breaks=c(23,100,5000,27000))