如何更改geom_point中的颜色或ggplot中的行

Question

我有这样的数据

data<- structure(list(sample = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 2L), .Label = c("A", 
"B"), class = "factor"), y = c(0.99999652, 0.99626012, 0.94070452, 
0.37332406, 0.57810894, 0.37673758, 0.22784684, 0.35358141, 0.21253558, 
0.17715703, 0.99999652, 0.86403956, 0.64054516, 0.18448824, 0.40362691, 
0.10791682, 0.06985696, 0.07384465, 0.0433271, 0.02875159), time = c(100L, 
150L, 170L, 180L, 190L, 220L, 260L, 270L, 300L, 375L, 100L, 150L, 
170L, 180L, 190L, 220L, 260L, 270L, 300L, 375L), x = c(0.9999965, 
0.9981008, 0.9940164, 1.0842966, 0.9412978, 1.0627907, 0.9135079, 
1.1982235, 0.9194105, 0.9361713, 0.9999965, 1.0494051, 0.9526752, 
1.1594711, 0.9827104, 1.0223711, 1.1419197, 1.0328598, 0.6015229, 
0.3745817)), .Names = c("sample", "y", "time", "x"), class = "data.frame", row.names = c(NA, 
-20L))

我有兴趣用黑色和红色等服装颜色绘制它。

我可以用两种随机的不同颜色来绘制它，但问题是

ggplot() + 
geom_point(data = data, aes(x = time, y = y, color = sample),size=4)

如果我想将第一个（A）指定为黑色而将（B）指定为红色。我怎样才能做到这一点？

Answer 1

您可以使用scale_color_manual：

ggplot() + 
  geom_point(data = data, aes(x = time, y = y, color = sample),size=4) +
  scale_color_manual(values = c("A" = "black", "B" = "red"))

根据OP的评论，要获得与您可以执行的点颜色相同的行：

ggplot(data = data, aes(x = time, y = y, color = sample)) + 
  geom_point(size=4) + 
  geom_line(aes(group = sample)) + 
  scale_color_manual(values = c("A" = "black", "B" = "red"))

Answer 2

我会这样做（你也可以使用十六进制颜色而不是红色，黑色）

data <- data %>% 
  mutate(Color = ifelse(sample == "A", "black",
                 ifelse(sample == "B", "red", "none")))

ggplot() + 
  geom_point(data = data, aes(x = time, y = y, color = Color),size=4)+
  scale_color_identity()