R-如何将双变量图例添加到我的ggplot2图表？

library(ggplot2)

# 创建示例数据
data <- data.frame(x = 1:10, y = 1:10, z = 1:10)

# 创建散点图，并添加双变量图例
ggplot(data, aes(x, y, color = z)) +
  geom_point() +
  scale_fill_gradient(low = "blue", high = "red", name = "Z值")

library(ggplot2)

# 创建示例数据
data <- data.frame(x = 1:10, y = 1:10, z = rep(c("A", "B"), each = 5))

# 创建散点图，并添加双变量图例
ggplot(data, aes(x, y, fill = z)) +
  geom_point(shape = 21, size = 5) +
  scale_fill_gradient2(low = "blue", mid = "white", high = "red", name = "Z类别")