r - 如何将孕龄(以周.天为单位)放在ggplot中的x轴上

Question

我正在尝试绘制一段时间内胎儿的体重。
Y 轴是以克为单位的胎儿体重
x 轴的格式需要如下所示:
7周3天==27.3
29 周 6 天 == 29.6
等等

我的数据(df)看起来像这样

weight age
2013   22.4
2302   25.6
2804   27.2
3011   29.1

我尝试过类似的方法...但不知道如何调整比例...

ggplot(df, aes(x = age, y = weight)) + 
geom_point() +
scale_x_continuous()

如果我得到年龄的实际数值(即 22.4 == 22weeks + 4/7days == 22.57)，
是否可以用我想要的标签来标记对应的年龄值？
例如...

weight age.label age.value
2013   22.4      22.57
2302   25.6      25.86
2804   27.2      27.29
3011   29.1      29.14

当我这样称呼时:

df <- df %>% mutate(age.label = as.character(age.label))

ggplot(df, aes(x = age.value, y = weight)) + 
geom_point() +
scale_x_continuous(label = "age.label")

我得到以下信息...

f(..., self = self) 中的错误:中断和标签的长度不同

非常感谢任何帮助

Answer 1

我借用了这个answer还有这个one ，创建一个变量刻度标签，使用格式来分隔天和周。

我提供了三种不同的方法。

1. 仅在每天的点放置刻度，但不对其进行编号。
2. 正确计算天和周，并通过将周设为粗体、将日期设为浅灰色来区分它们。
3. 与 2 相同，但使用大小。这种方法效果不太好，因为它在标签和绘图之间造成了很大的差距。它被包含在内是为了完整性......并希望有人告诉我如何修复它。

下图是第二种方法。

我认为垂直刻度线也可以着色，这样如果您愿意，其中一些也可以消失。

library(ggplot2)
library(tidyverse)
df<-read.table(header=TRUE, text="weight age.label age.value

2013   22.4      22.57
2302   25.6      25.86
2804   27.2      27.29
3011   29.1      29.14")


#have ticks for every day using 1/7 distance tick marks
ggplot(df, aes(x = age.value, y = weight)) + 
  geom_point() +
  scale_x_continuous(limits=c(22, 30), 
                     minor_breaks = seq(from = 1, to = 33, by = 1/7),
                     breaks = 1:30) 


#create a df of tick marks labels containing day number and week number
breaks_labels_df  <- data.frame(breaks = seq(from = 1, to = 33, by = 1/7)) %>%
  mutate(minors= rep(0:6, length.out = nrow(.)),
         break_label = ifelse(minors == 0, breaks, minors))

#plot both day number and week number differentiating between them by the label formatting.
#remove the minor tick lines to reduce the busyness of the plot
ggplot(df, aes(x = age.value, y = weight)) + 
  geom_point() +
  scale_x_continuous(limits=c(22, 30), 
                     breaks = seq(from = 1, to = 33, by = 1/7),
                     labels  = breaks_labels_df$break_label)  +
  theme(axis.text.x = element_text(color = c("grey60","grey60","black",rep("grey60",4)), 
                                   size = 8, angle = 0, 
                                   hjust = .5, vjust = .5,
                                   face = c("plain","plain","bold",rep("plain",4))),
        panel.grid.minor.x = element_blank()) +
  labs(title = "Baby weight in relation to age", x = "Age in weeks and days", y = "weight in grams")



#Changing the font size places a large gap between the tick labels and the axis
ggplot(df, aes(x = age.value, y = weight)) + 
  geom_point() +
  scale_x_continuous(limits=c(22, 30), 
                     breaks = seq(from = 1, to = 33, by = 1/7),
                     labels  = breaks_labels_df$break_label) +
     theme(axis.text.x = element_text(vjust = 0, size = c(8,8,12,rep(8,4)), 
                                      margin =  margin(t = 0), lineheight = 0))