如何强制geom_density从(0,0)开始？

Question

geom_density 问题:如何强制从(0，0)开始？

我制作了这个情节：

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使用此代码(欢迎输入如何改进脚本)：

ki60low <- subset(p, p$ki67in==0 & p$recurrence==1)
ki60in <- subset(p, p$ki67in==1 & p$recurrence==1)
ki60high <- subset(p, p$ki67in==2 & p$recurrence==1)

ki60low$time.recur.months1 <- ki60low$time.recur.months/12
ki60in$time.recur.months1 <- ki60in$time.recur.months/12
ki60high$time.recur.months1 <- ki60high$time.recur.months/12

theme <- theme(axis.line = element_line(colour = "black"),
               panel.grid.major = element_line(colour = "gray98"),
               panel.grid.minor = element_line(colour = "gray98"),
               panel.border = element_blank(),
               panel.background = element_blank())

ggplot()  + theme +
  scale_x_continuous(name="Years to recurrence", breaks=c(0,1,2,3,4,5,6,7,8,9,10,11), labels=c("0","1","2","3","4","5","6","7","8","9","10","11"), limits=c(-1,11)) +
  scale_y_continuous(name="Number of recurrences", limits=c(0, 6), seq(0,6,by=1)) +

  geom_bar(aes(x=ki60low$time.recur.months1), colour="#1C73C2", fill="#1C73C2", alpha=0.2)  + 
  geom_bar(aes(x=ki60in$time.recur.months1), colour="red", fill="red", alpha=0.2) +
  geom_bar(aes(x=ki60high$time.recur.months1), colour="black", fill="black", alpha=0.7) +

  geom_density(aes(x=ki60low$time.recur.months1, y=..count..), colour="#1C73C2", fill="#1C73C2", alpha=0.1)  + 
  geom_density(aes(x=ki60in$time.recur.months1, y=..count..), colour="red", fill="red", alpha=0.1) +
  geom_density(aes(x=ki60high$time.recur.months1, y=..count..), colour="black", fill="black", alpha=0.18) +

  annotate("label", x = 8.28, y = 5.5, label = "Ki-67 proliferative index: 0 - 4%", label.size = 0.5, cex=8, colour="#1C73C2") +
  annotate("label", x = 8.28, y = 4.5, label = "Ki-67 proliferative index: 5 - 9%", label.size = 0.5, cex=8, colour="red") +
  annotate("label", x = 8.28, y = 3.5, label = "Ki-67 proliferative index: \u226510% ", label.size = 0.5, cex=8, colour="black") +

  theme(axis.text.x = element_text(color = "grey20", size = 12), axis.title.x = element_text(color = "grey20", size = 14, face="bold", margin=margin(t=12))) +
  theme(axis.text.y = element_text(color = "grey20", size = 11), axis.title.y = element_text(color = "grey20", size = 14, face="bold", margin=margin(r=12))) +
  theme(legend.text=element_text(size=12)) + theme(legend.title=element_text(size=14)) 

我希望geom_density从(0,0)开始。这是如何做到的呢？我找到了this，但这没有帮助。

我的数据p

p <- structure(list(ki67in = c(0L, 2L, 0L, 0L, 1L, 0L, 2L, 2L, 1L, 
0L, 1L, 2L, 0L, 2L, 0L, 1L, 1L, 1L, 0L, 2L, 2L, 0L, 1L, 1L, 0L, 
0L, 0L, 1L, 0L, 1L, 2L, 0L, 1L, 1L, 0L, 1L, 0L, 1L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 1L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 2L, 
1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 2L, 0L, 0L, 1L, 0L, 1L, 0L, 
0L, 1L, 0L, 0L, 1L, 2L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 1L, 
0L, 0L, 1L, 1L, 2L, 0L, 2L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 
1L, 0L, 2L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 2L, 
0L, 0L, 0L, 0L, 1L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L), time.recur.months = c(0.75, 0.6, 4.665297741, 
0.1, 0.75, 1, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 6, 7, 8, 8, 
8, 9, 11, 12, 13, 13, 15, 15, 15, 16, 17, 17, 18, 27, 28, 29, 
30, 33, 34, 35, 37, 37, 38, 39, 40, 41, 45, 49, 49, 50, 52, 53, 
54, 56, 56, 56, 56, 57, 58, 58, 60, 60, 60, 60, 61, 62, 63, 64, 
66, 67, 67, 72, 72, 74, 78, 80, 80, 80, 81, 82, 83, 83, 84, 84, 
85, 85, 86, 86, 88, 88, 88, 88, 89, 89, 89, 90, 90, 91, 91, 92, 
92, 92, 92, 93, 93, 93, 93, 93, 93, 94, 97, 98, 98, 99, 99, 99, 
100, 101, 101, 101, 103, 103, 103, 103, 104, 104, 106, 106, 109, 
110, 111, 111, 112, 114, 114, 115, 116, 117, 118, 118, 118, 119, 
120, 120, 120, 120, 120, 120, 121, 121, 123, 124, 124, 125, 125, 
125, 125), recurrence = c(0L, 0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 
0L, 1L, 0L, 0L, 1L, 0L, 1L, 0L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 0L, 
1L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 1L, 1L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 1L, 1L, 0L, 1L, 
0L, 0L, 1L, 1L, 1L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L, 1L, 1L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 0L, 1L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 1L, 0L, 0L, 0L, 0L)), class = "data.frame", row.names = c(1L, 
2L, 3L, 9L, 10L, 11L, 12L, 13L, 14L, 15L, 16L, 18L, 19L, 20L, 
21L, 22L, 23L, 24L, 25L, 26L, 27L, 28L, 29L, 30L, 31L, 32L, 33L, 
34L, 35L, 36L, 37L, 38L, 39L, 40L, 41L, 44L, 45L, 46L, 47L, 48L, 
49L, 50L, 51L, 52L, 53L, 54L, 55L, 57L, 59L, 60L, 61L, 62L, 63L, 
64L, 65L, 66L, 67L, 68L, 69L, 70L, 71L, 72L, 73L, 74L, 75L, 76L, 
77L, 78L, 79L, 80L, 81L, 82L, 83L, 84L, 85L, 87L, 89L, 90L, 91L, 
92L, 93L, 94L, 96L, 97L, 98L, 99L, 100L, 101L, 102L, 103L, 104L, 
105L, 106L, 107L, 109L, 110L, 111L, 112L, 113L, 114L, 115L, 116L, 
117L, 118L, 119L, 120L, 121L, 123L, 124L, 125L, 126L, 127L, 128L, 
130L, 131L, 132L, 133L, 134L, 135L, 136L, 137L, 138L, 139L, 140L, 
141L, 142L, 143L, 144L, 145L, 146L, 147L, 148L, 149L, 150L, 151L, 
152L, 153L, 154L, 155L, 156L, 157L, 158L, 159L, 160L, 161L, 162L, 
163L, 164L, 165L, 166L, 167L, 168L, 169L, 170L, 171L, 172L, 173L, 
174L, 175L))

Answer 1

一些更改将允许您用更少的代码生成您的情节：

1)使用带有类别列的单个数据框架，该列将映射到颜色和填充美学，而不是单独的数据帧。那么您只需要给每个geom打一次电话。

2)直接从数据生成图例，而不是使用注释。

3)修改现有的情节主题(本例中为theme_classic())。

4)使用scale_x/y_continuous()设置中断时，您通常可以利用各种捷径。例如：0:11而不是c(0,1,2,3,4,5,6,7,8,9,10,11)。另外，如果标签与中断值相同，那么就不需要添加labels参数。

此外:我已经从geom_bar转到了geom_rug，但是如果您愿意的话，当然可以使用条形图。对于地毯图，我稍微抖动了一些标记，这样就会显示出所有具有相同x值的点，而不是在另一个上面绘制。此外，对于ggplot，使用裸列名，而不是重新声明数据框架名称。例如，在原始代码中，aes(time.recur.months1, ...)而不是aes(ki60low$time.recur.months1, ...)。

对于轴限值，我不知道你想让它们看起来怎样。你把x轴的极限设为c(-1,11)。从零开始，有两个选择：

当计算密度时，

• scale_x_continuous(limits=c(0,11))将排除该范围以外的数据，estimate.
• coord_cartesian(xlim=c(0,11))将包括密度估计中的所有数据，即使它超出了xlim范围。

在这两种情况下，默认情况下，ggplot都会在轴限制之前和之后添加一些填充。如果希望填充较少或不填充，请在expand中使用scale_x/y_continuous参数。

library(tidyverse)
library(ggstance)

p.for.plot = p %>% 
  filter(recurrence==1) %>% 
  arrange(ki67in) %>% 
  mutate(time.recur.years=time.recur.months/12,
         ki67in=recode(ki67in, 
                       "0"="Ki-67 proliferative index: 0 - 4%",
                       "1"="Ki-67 proliferative index: 5 - 9%",
                       "2"="Ki-67 proliferative index: \u226510%"),
         ki67in=factor(ki67in, levels=unique(ki67in)))

cols = c("#1C73C2", "red", "black")

ggplot(p.for.plot, aes(time.recur.years, colour=ki67in, fill=ki67in)) +
  geom_density(aes(y=..count..), alpha=0.2) + 
  #geom_bar(alpha=0.7) +
  geom_rug(aes(y=0), position=position_jitter(width=0.05, height=0), 
           length=unit(0.05, "npc"), show.legend=FALSE) +
  coord_cartesian(xlim=c(0,11)) +
  scale_x_continuous(name="Years to recurrence", breaks=0:11, expand=c(0,0)) +
  scale_y_continuous(name="Number of recurrences", limits=c(0, 6), breaks=0:6, expand=c(0,0)) +
  scale_colour_manual(values=cols) +
  scale_fill_manual(values=cols) + 
  labs(colour="", fill="") +
  theme_classic() +
  theme(panel.grid.major = element_line(colour = "gray98"),
        panel.grid.minor = element_line(colour = "gray98"),
        legend.position=c(0.7,0.8))

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