ggplot2条形图刻度位置和自定义图例问题

Question

我有这样的ggplo条形图

创建于

library(lubridate)
library(ggplot2)
library(grid)
library(scales)

### Set up dummy data.
dayVec     <- seq(ymd('2016-01-01'), ymd('2016-01-10'), by = '1 day')
dayCount   <- length(dayVec)
dayValVec1 <- c(0,-0.25,0.15,0.3,0.4,0.10,0.17,0.22,0.50,0.89)
dayValVec2 <- c(0.15,0.2,-0.17,0.6,0.16,0.41,0.55,0.80,0.90,1.00)
dayValVec3 <- dayValVec2
dayDF      <- data.frame(Date = rep(dayVec, 3),
                     DataType = factor(c(rep('A', dayCount), rep('B',     dayCount), rep('C', dayCount))),
                     Value = c(dayValVec1, dayValVec2, dayValVec3))

p <- ggplot(dayDF,aes(Date, Value, colour = DataType)) +
theme_bw() +
ggtitle("Chart Title \n") +
scale_color_manual("",values = c("#033563", "#E1E2D2"),labels = c("xxx ", "yyy     ")) +
geom_rect(aes(xmin = ymd(min(dayDF$Date)), 
            xmax = ymd('2016-01-06'),
            ymin = -Inf,
            ymax = Inf
), fill = "#E1E2D2", alpha = 0.1, colour = "#E1E2D2") +
geom_bar(stat = "identity", fill = "#033563", colour = "#033563") +
geom_hline(yintercept = 0, size = 1) +
scale_x_datetime(expand = c(0,0), labels = date_format('%b-%d'), breaks =  date_breaks('1 day')) +
scale_y_continuous(expand = c(0,0), labels = percent, limits =  c(min(dayDF$Value)*1.2, max(dayDF$Value)*1.2)) +
theme(axis.text.x  = element_text(angle = 90), 
    axis.title.x = element_blank(), 
    axis.title.y = element_blank(),
    panel.grid.minor = element_blank(),
    panel.grid.major.x = element_blank(),
    panel.grid.major.y = element_line(size = 0.5, colour = "black"),
    axis.line  = element_line(size = 1),
    axis.ticks = element_line(size = 1),
    axis.text  = element_text(size = 20, colour = "#033563"),
    axis.title.x = element_text(hjust = 2),
    plot.title = element_text(size = 40, face = "bold", colour = "#033563"),
    legend.position = 'bottom',
    legend.text = element_text(colour = "#033563", size = 20),
    legend.key  = element_blank(),
    panel.border = element_rect(colour = "black", fill = NA, size = 1.5)
)
p

现在我要解决问题，首先我要让goem_rect从0开始而不是在第一个柱的中心，这里的问题似乎是日期x轴。 其次，我想拥有这样的传奇

在图表的底部。 我尝试创建一个虚拟数据系列以获取两个图例条目，但它甚至不显示图例。 我希望可以在不干扰数据的情况下操纵图例。 “ yyy”图例条目应指示阴影表示的内容。 在此先感谢您，我是ggplot2的新手。

Answer 1

这是一个解决方案：

1. 由于格式， geom_rect()第一个问题。

我更喜欢POSIXct ，所以我可以轻松地修改x轴：

geom_rect(aes(xmin = as.POSIXct("2015-12-31 12:00:00"), 
        xmax = as.POSIXct("2016-01-06 12:00:00"),
        ymin = -Inf,
        ymax = Inf, 
        fill = "#E1E2D2"),
        color = "#E1E2D2", alpha = 0.1)

提示：如果要完全填充1月6日，请开始"2015-12-31 12:00:00"以扩展geom_rect()并结束"2016-01-06 12:00:00" 。

---

2. 传说

您应该使用scale_fill_manual()而不是scale_color_manual()
并且您必须将fill参数放入geom_rect()和geom_bar() aes内。

---

码：

library(lubridate)
library(ggplot2)
library(grid)
library(scales)

dayVec     <- seq(as.POSIXct('2016-01-01'), as.POSIXct('2016-01-10'), by = '1 day')
dayCount   <- length(dayVec)
dayValVec1 <- c(0,-0.25,0.15,0.3,0.4,0.10,0.17,0.22,0.50,0.89)
dayValVec2 <- c(0.15,0.2,-0.17,0.6,0.16,0.41,0.55,0.80,0.90,1.00)
dayValVec3 <- dayValVec2
dayDF      <- data.frame(Date = rep(dayVec, 3),
                 DataType = factor(c(rep('A', dayCount), rep('B',     dayCount), rep('C', dayCount))),
                 Value = c(dayValVec1, dayValVec2, dayValVec3))
dayDF$Date = as.POSIXct(dayDF$Date)

p <- ggplot(dayDF,aes(Date, Value, colour = DataType)) +
theme_bw() +
ggtitle("Chart Title \n") +
geom_rect(aes(xmin = as.POSIXct("2015-12-31 12:00:00"), 
        xmax = as.POSIXct("2016-01-06 12:00:00"),
        ymin = -Inf,
        ymax = Inf, 
        fill = "#E1E2D2"),
        color = "#E1E2D2", alpha = 0.1) +
geom_bar(aes(fill = "#033563"), color = "#033563", stat = "identity") +
geom_hline(yintercept = 0, size = 1) +
scale_x_datetime(expand = c(0,0), labels = date_format('%b-%d'), breaks =  date_breaks('1 day')) +
scale_y_continuous(expand = c(0,0), labels = percent, limits =  c(min(dayDF$Value)*1.2, max(dayDF$Value)*1.2)) +
theme(axis.text.x  = element_text(angle = 90), 
axis.title.x = element_blank(), 
axis.title.y = element_blank(),
panel.grid.minor = element_blank(),
panel.grid.major.x = element_blank(),
panel.grid.major.y = element_line(size = 0.5, color = "black"),
axis.line  = element_line(size = 1),
axis.ticks = element_line(size = 1),
axis.text  = element_text(size = 20, color = "#033563"),
axis.title.x = element_text(hjust = 2),
plot.title = element_text(size = 40, face = "bold", colour = "#033563"),
legend.position = 'bottom',
legend.text = element_text(color = "#033563", size = 20),
legend.key  = element_blank(),
panel.border = element_rect(color = "black", fill = NA, size = 1.5)
) +
scale_fill_manual("",values = c("#033563", "#E1E2D2"),labels = c("xxx ", "yyy "))
p

PS：我必须在scale_x_datetime(label = date_format())指定tz = "Europe/Paris"以具有正确的日期，具体取决于位置。