如何使用 ggplot2 在 for 循环中从数据框生成绘图标题？

Question

我想从我正在使用的数据框中为 for 循环生成的每个图生成 ggsave 的图标题和文件名。

我希望在我的情节标题中将月份写成一月、二月、三月等，而不是 1、2、3。我怎样才能以优雅的方式做到这一点？

例如，如果我为 1 月绘制 A1 和 B1，我希望标题为 A1 和 B1，2016 年 1 月，下个月：A1 和 B1 表示 2016 年 2 月 等等。我希望每个月的每个情节的文件名都有类似的东西。对于标题，月份显示为“1”，根本不显示 2016 年。对于文件名，它按原样工作，但每次更改 AA och BB 时我都必须更改它，如果我不必这样做，我会很高兴的。

我还希望从我过滤的任何数据中生成它，所以如果我过滤 2016 年 1 月的 A1 和 B1，我希望它转移到标题中，而无需我每个月都输入它。

我制作了一个数据框来解决这个问题（实际的数据框当然很大，而且我的 R 脚本很长）。

crs <- CRS("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs") 

Number <- 1:48 

AA <-  c(rep("A1", 12), rep("A2", 12), rep("A3", 12),rep("A4", 12))

BB <- c(rep("B4", 12), rep("B3", 12), rep("B2", 12),rep("B1", 12))

Long <- c(-46.25, -45.85,-45.85,-45.65, -45.983, -45.95,-45.85, -47.116,-47.1,-47.65, -47.116,-47.65, 
          -47.1,-47.633,-47.116,-47.65, -47.1, -47.65, -47.116, -47.666, -46.866, -47.116, -47.783, -47,
          -46.25, -45.85, -45.85, -45.65, -45.983, -45.95, -45.85, -47.116, -47.1, -47.65, -47.116, -47.65
          -47.1, -47.633, -47.116, -47.65, -47.1, -47.65, -47.116, -47.666, -46.866, -47.116, -47.783, -47, -47)

Lat <- c(46.55, 46.416, 46.533, 46.45, 46.433, 46.433, 46.45, 48.116, 48.083, 48.133, 48.1, 48.133, 
         48.1, 48.133, 48.116, 48.15, 48.1, 48.133, 48.1, 48.133, 48.133, 48.116, 48, 47.683, 
         46.55, 46.416, 46.533, 46.45, 46.433, 46.433, 46.45, 48.116, 48.083, 48.133, 48.1, 48.133,
         48.1, 48.133, 48.116, 48.15, 48.1, 48.133, 48.1, 48.133, 48.133, 48.116, 48, 47.683)

End_month <-  sample(1:12, size=48, replace = TRUE)

Category1 <- c(rep("Yes", 16), rep("No", 16), rep("Maybe", 16))
Category <- sample(x = Category1, size = 48)

Year<- c(rep("2016", 48))


dfAllData2 <- data.frame(Number, Long, Lat, End_month, Year, Category,
                           AA, BB )

#

newdata2 <- c("Lat", "Long", "End_month","Year", "AA", "BB", "Category" ) # select the column names of the columns in the plot

dfSubsets <- dfAllData2[newdata2] 


# filter and create 2 layers of data----


Month_list <- (unique(dfSubsets$End_month))                   



for (i in seq_along(Months_list)){

dfFiltered1 <- dfSubsets %>%
               filter(AA=="A1"& BB=="B1")



  #create 2 sets of data


  dfLayer1 <- dfFiltered1 %>%
    filter(Category %in% c("Yes","No" ))


  dfLayer2 <- dfFiltered1 %>%
    filter(Category == "Maybe" )


  #Plot ----

myPlot <- plot(dfFiltered1$Long, dfFiltered1$Lat)

ggplot(myPlot) +
    geom_point(data = dfLayer1, aes(Long, Lat, color=Category, shape = Category), size = 2 ) + guides(size= FALSE)+
    geom_point (data = dfLayer2, aes(Long, Lat, color=Category, shape = Category), size = 2 ) + guides(size= FALSE)


  myPlot <- ggplot(myPlot) +
    geom_point(data = dfLayer1, aes(Long, Lat, color=Category, shape = Category), size = 2 ) + guides(size= FALSE)+
    geom_point (data = dfLayer2, aes(Long, Lat, color=Category, shape = Category), size = 2 ) + guides(size= FALSE)


  print(myPlot + coord_cartesian(xlim = c(-43, -55), ylim = c(39, 49)) + 
          theme_bw()+
          theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank(), 
                plot.title = element_text(hjust = 0, face = "bold", size = 14), 
                legend.justification = c(0,1), legend.position = c(0,1), legend.background = element_rect(color = "black"))+
          ggtitle("A1, and B1,", Month_list[i], "2016")+
          labs(x = "Longitude", y = "Latitude"))

  ggsave(paste("A1_B1_", Month_list[i],"_2016", ".png"))
}

Answer 1

试试这个。代码在整个月份循环。但我只包括了前三个地块。另外：我还整理了代码。

library(tidyverse)
library(sp)

crs <-sp::CRS("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs") 

Number <- 1:48 

AA <-  c(rep("A1", 12), rep("A2", 12), rep("A3", 12),rep("A4", 12))

BB <- c(rep("B4", 12), rep("B3", 12), rep("B2", 12),rep("B1", 12))

Long <- c(-46.25, -45.85,-45.85,-45.65, -45.983, -45.95,-45.85, -47.116,-47.1,-47.65, -47.116,-47.65, 
          -47.1,-47.633,-47.116,-47.65, -47.1, -47.65, -47.116, -47.666, -46.866, -47.116, -47.783, -47,
          -46.25, -45.85, -45.85, -45.65, -45.983, -45.95, -45.85, -47.116, -47.1, -47.65, -47.116, -47.65
          -47.1, -47.633, -47.116, -47.65, -47.1, -47.65, -47.116, -47.666, -46.866, -47.116, -47.783, -47, -47)

Lat <- c(46.55, 46.416, 46.533, 46.45, 46.433, 46.433, 46.45, 48.116, 48.083, 48.133, 48.1, 48.133, 
         48.1, 48.133, 48.116, 48.15, 48.1, 48.133, 48.1, 48.133, 48.133, 48.116, 48, 47.683, 
         46.55, 46.416, 46.533, 46.45, 46.433, 46.433, 46.45, 48.116, 48.083, 48.133, 48.1, 48.133,
         48.1, 48.133, 48.116, 48.15, 48.1, 48.133, 48.1, 48.133, 48.133, 48.116, 48, 47.683)

End_month <-  sample(1:12, size=48, replace = TRUE)

Category1 <- c(rep("Yes", 16), rep("No", 16), rep("Maybe", 16))
Category <- sample(x = Category1, size = 48)

Year<- c(rep("2016", 48))

dfAllData2 <- data.frame(Number, Long, Lat, End_month, Year, Category,
                         AA, BB )

newdata2 <- c("Lat", "Long", "End_month","Year", "AA", "BB", "Category" ) # select the column names of the columns in the plot

dfSubsets <- dfAllData2[newdata2] 

# filter and create 2 layers of data----

Month_list <- unique(dfSubsets$End_month)

## BUG: when using seq_along this way, `i` no longer is the number of the month
#for (i in seq_along(Month_list)){
# Therefore: simply use  for (i in Month_list)
##
for (i in Month_list) {

  print(i)
  print(month.name[i])

  dfFiltered1 <- dfSubsets %>%
    filter(AA=="A1"& BB=="B4") %>% 
    filter(End_month == i)

  #create 2 sets of data

  dfLayer1 <- dfFiltered1 %>%
    filter(Category %in% c("Yes","No" ))

  dfLayer2 <- dfFiltered1 %>%
    filter(Category == "Maybe" )

  #Plot ----

  myPlot <- ggplot(mapping = aes(Long, Lat)) +
    geom_point(data = dfFiltered1)+
    geom_point(data = dfLayer1, aes(color=Category, shape = Category), size = 2 ) + 
    geom_point (data = dfLayer2, aes(color=Category, shape = Category), size = 2 ) + guides(size= FALSE)

  myPlot <- myPlot + 
    coord_cartesian(xlim = c(-43, -55), ylim = c(39, 49)) + 
    theme_bw()+
    theme(panel.grid.major = element_blank(), panel.grid.minor = element_blank(), 
          plot.title = element_text(hjust = 0, face = "bold", size = 14), 
          legend.justification = c(0,1), legend.position = c(0,1), legend.background = element_rect(color = "black"))+
    ggtitle(paste("A1, and B1,", month.name[[i]], "2016"))+
    labs(x = "Longitude", y = "Latitude")
  print(myPlot)

  ggsave(paste("A1_B1_", month.name[[i]],"_2016", ".png"))
}
#> [1] 11
#> [1] "November"
#> Saving 7 x 5 in image

#> [1] 5
#> [1] "May"
#> Saving 7 x 5 in image

#> [1] 1
#> [1] "January"
#> Saving 7 x 5 in image

^{由reprex package (v0.3.0) 于 2020-03-16 创建}