如何使用函数将 geom_rect 个对象从数据框添加到 ggplot

Question

我正在尝试在 r 中创建一个复合图，其代码如下：

    #Adding initial data
ggp <- ggplot(NULL, aes(x = date, y = covid)) + 
  geom_spline(data = onsdf, 
              aes(x = date, y = covid, colour = "ONS Modelled Estimates"), nknots = 90, size = 1.3) +
  geom_spline(data = gvtdf, 
              aes(x = date, y = covid, colour = "Gvt Reported Positive Tests"), nknots = 90, size = 1.3) 

#Creating function to add stringency bars
barfunction <- function(date1, date2, alpha){
  a <- annotate(geom = "rect",
                xmin = as.Date(date1), xmax = as.Date(date2), ymin = 0, ymax = Inf, alpha = alpha, fill = "red")
  return(a)
}

#Adding lockdown stringency bars
ggp <- ggp + 
  barfunction("2020-05-03", "2020-06-01", 0.5) +
  barfunction("2020-06-01", "2020-06-15", 0.4) +
  barfunction("2020-06-15", "2020-09-14", 0.3) +
  barfunction("2020-09-14", "2020-11-05", 0.3) +
  barfunction("2020-11-05", "2020-12-02", 0.5) +
  barfunction("2020-12-02", "2021-01-06", 0.4) +
  barfunction("2021-01-06", "2021-03-29", 0.5) +
  barfunction("2021-03-29", "2021-04-12", 0.4) +
  barfunction("2021-04-12", "2021-05-17", 0.3) +
  barfunction("2021-05-17", "2021-07-19", 0.2) +
  barfunction("2021-07-19", "2021-12-08", 0.1) +
  barfunction("2021-12-08", "2022-02-24", 0.2) +


#Adding plot labels
ggp <- ggp + labs(title = "Estimated Total Covid-19 Cases vs Reported Positive Cases", 
       subtitle = "From ONS and HMGvt datasets", 
       x = "Date (year - month)", y = "Covid Levels") +
  scale_y_continuous(labels = scales::comma) +
  scale_x_date(limits = as.Date(c("2020-05-03", NA ))) +
  scale_colour_manual(name = "Measurement Method",
                      values = c("ONS Modelled Estimates"="purple", 
                                 "Gvt Reported Positive Tests" = "blue"))

此代码的输出如下所示：

Rendered graph

如您所见，我想更改此代码中的一个非常重复的函数 (barfunction)。我认为最好的方法是将 barfunction() 应用于图形的数据转换为数据框，然后尝试在所述数据框上使用函数。这是数据框的头部（称为 strindf）

date1       date2       alpha
2020-05-03  2020-06-01  0.5
2020-06-01  2020-06-15  0.4
2020-06-15  2020-09-14  0.3
2020-09-14  2020-11-05  0.3

我最初尝试使用 apply() 将 strindf 数据添加到我的绘图中，但是我收到一条错误消息（as.Date(date2) 中的错误：缺少参数“date2”，没有默认值).这是我如何将其实现到原始代码中

ggptest <- ggplot(NULL, aes(x = date, y = covid)) + 
  geom_spline(data = onsdf, 
              aes(x = date, y = covid, colour = "ONS Modelled Estimates"), nknots = 90, size = 1.3) +
  geom_spline(data = gvtdf, 
              aes(x = date, y = covid, colour = "Gvt Reported Positive Tests"), nknots = 90, size = 1.3) +
  apply(strindf, MARGIN = 1 , barfunction) +
  theme_minimal() +
  scale_y_continuous(labels = scales::comma) +
  scale_x_date(limits = as.Date(c("2020-05-03", NA ))) +
  scale_colour_manual(name = "Legend",

我对 r 很陌生，所以有点难过，有人有什么建议吗？

提前致谢！

Answer 1

你的想法是对的。但是您从 apply 函数族中选择了错误的函数。因为你有多个参数的函数，所以使用 mapply 或者像我在下面做的那样 purrr::pmap:

使用一些伪造的随机示例数据：


library(ggplot2)
library(ggformula)

barfunction <- function(date1, date2, alpha) {
  annotate(geom = "rect", xmin = as.Date(date1), xmax = as.Date(date2), ymin = 0, ymax = Inf, alpha = alpha, fill = "red")
}

ggplot(NULL, aes(x = date, y = covid)) +
  geom_spline(data = df, aes(colour = "ONS Modelled Estimates"), nknots = 90, size = 1.3) +
  purrr::pmap(strindf, barfunction) +
  theme_minimal() +
  scale_y_continuous(labels = scales::comma) +
  scale_x_date(limits = as.Date(c("2020-05-03", NA))) +
  scale_colour_manual(
    name = "Measurement Method",
    values = c(
      "ONS Modelled Estimates" = "purple",
      "Gvt Reported Positive Tests" = "blue"
    )
  )
#> Warning: Removed 123 rows containing non-finite values (stat_spline).

数据

set.seed(123)

df <- data.frame(
  date = seq.Date(as.Date("2020-01-01"), as.Date("2020-12-31"), by = "day"),
  covid = runif(366)
)

strindf <- structure(list(date1 = c(
  "2020-05-03", "2020-06-01", "2020-06-15",
  "2020-09-14"
), date2 = c(
  "2020-06-01", "2020-06-15", "2020-09-14",
  "2020-11-05"
), alpha = c(0.5, 0.4, 0.3, 0.3)), class = "data.frame", row.names = c(
  NA,
  -4L
))

如何使用函数将 geom_rect 个对象从数据框添加到 ggplot

How to use function to add geom_rect objects to ggplot from a data frame

r

function

ggplot2