ggplot2画简单的heatmap

gg_heatmap

ggplot2 heatmap

偶然的机会，发现ggplot2画的heatmap也挺好看的，除了不能画出聚类树来(手动滑稽)。 随意新建了两个矩阵，并且计算对应的相关系数。

x <- matrix(sample(1:1000, 100), ncol = 10)
y <- matrix(sample(1:1000, 100), ncol = 10)
cor_score <- cor(t(x), t(y))
plot_df <- data.frame(
  x = rep(1:10, 10),
  y =rep(1:10, rep(10,10)),
  value = as.vector(cor_score)
)

利用geom_tile()画矩形，就大致完成了heatmap图。

ggplot(data = plot_df, aes(x,y)) +
  geom_tile(aes(fill = value)) +
  scale_fill_continuous(low = "#00FF00", high = "#FF0000") +
  scale_x_continuous(breaks = 1:10, labels = paste("sample", 1:10, sep = "_"))+
  scale_y_continuous(breaks = 1:10, labels = paste("gene", 1:10, sep = "_"))+
  theme_bw() +
  theme(
    axis.ticks = element_blank(),
    panel.grid = element_blank(),
    panel.border = element_blank(),
    axis.title = element_blank(),
    axis.text.x = element_text(angle = 90)
  )

更进一步，发现可以利用极坐标画出圆形的heatmap，挺有意思的，主要还是计算文字旋转的角度。

text <- paste("gene", 1:10, sep = "_")
one_cir_ang = 360/nrow(x)
right_text_ang <- -(seq(one_cir_ang/2, (180 - one_cir_ang/2), by = one_cir_ang))
right_text_ang[which(right_text_ang < -90)] <- 180 + right_text_ang[which(right_text_ang < -90)]
left_text_ang <- right_text_ang
text_ang = c(right_text_ang, left_text_ang)

然后就利用scale_y_discrete和coord_polar(theta = "x")转换为极坐标

ggplot(data = plot_df, aes(x,y)) +
  geom_tile(aes(fill = value)) +
  geom_text(
    aes(x = x, y = y,label = text, angle = text_ang),
    data = data.frame(x = 1:10, y = 12, text, text_ang),
    ) +
  scale_fill_continuous(low = "#00FF00", high = "#FF0000") +
  scale_y_discrete(breaks = 1:10, labels = paste("gene", 1:10, sep = "_"))+
  coord_polar(theta = "x") +
  theme_bw() +
  theme(
    axis.ticks = element_blank(),
    panel.grid = element_blank(),
    panel.border = element_blank(),
    axis.title = element_blank(),
    axis.text = element_blank()
  )

posted @ 2018-03-10 19:27  PeRl`  阅读(734)  评论(0)  编辑  收藏  举报