ggplot，条件填充 geom_point

Question

我正在寻找一种方法来填充geom_point如果满足条件

示例：

mydata <- tibble(x_var = 1:5, 
                 y_var = runif(5), 
                 category_a = c('yes', 'yes', 'no', 'no', 'yes'),
                 category_b = c('down', 'up', 'up', 'down', 'down')
                 )

ggplot(mydata,
       aes(x = x_var,
           y = y_var,
           color = category_a,
           )
       ) + 
  geom_point(shape = 21,
             size = 5,
             stroke = 2
             )

我想把满足条件category_b == 'down'的点用category_a相同的颜色填上，其余不填，怎么办？问候！

Answer 1

您可以在 fill 参数中添加填充条件。并添加透明色 scale_fill_discrete.

代码

mydata <- tibble(x_var = 1:5, 
                 y_var = runif(5), 
                 category_a = c('yes', 'yes', 'no', 'no', 'yes'),
                 category_b = c('down', 'up', 'up', 'down', 'down')
)

ggplot(mydata,
       aes(x = x_var,
           y = y_var,
           color = category_a,
           fill = ifelse(category_b == "down", category_a, NA)
       )
) + 
  geom_point(size = 5,
             shape = 21,
             stroke = 2) +
  scale_fill_discrete(na.value = "transparent") +
  guides(fill = FALSE)

情节

Answer 2

另一种方法是使用特定形状并手动分配它们。一个很好的副作用是更具描述性的图例：

mydata <- tibble(x_var = 1:5, 
                 y_var = runif(5), 
                 category_a = c('yes', 'yes', 'no', 'no', 'yes'),
                 category_b = c('down', 'up', 'up', 'down', 'down'))

# choose circle and dot shapes
shps <- c(1, 16)


ggplot(mydata, aes(x = x_var, y =  y_var, color = category_a, shape= category_b)) +
    geom_point(size = 5, stroke = 2) + 
    # add manually choosen shapes and colors
    scale_shape_manual(values=shapes)

ggplot，条件填充 geom_point

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