加入树形图和热图

时间:2017-02-05 02:17:14

标签: r ggplot2 heatmap dendrogram cowplot

我有heatmap(来自一组样本的基因表达):

set.seed(10)
mat <- matrix(rnorm(24*10,mean=1,sd=2),nrow=24,ncol=10,dimnames=list(paste("g",1:24,sep=""),paste("sample",1:10,sep="")))
dend <- as.dendrogram(hclust(dist(mat)))
row.ord <- order.dendrogram(dend)
mat <- matrix(mat[row.ord,],nrow=24,ncol=10,dimnames=list(rownames(mat)[row.ord],colnames(mat)))
mat.df <- reshape2::melt(mat,value.name="expr",varnames=c("gene","sample"))

require(ggplot2)
map1.plot <- ggplot(mat.df,aes(x=sample,y=gene))+geom_tile(aes(fill=expr))+scale_fill_gradient2("expr",high="darkred",low="darkblue")+scale_y_discrete(position="right")+
  theme_bw()+theme(plot.margin=unit(c(1,1,1,-1),"cm"),legend.key=element_blank(),legend.position="right",axis.text.y=element_blank(),axis.ticks.y=element_blank(),panel.border=element_blank(),strip.background=element_blank(),axis.text.x=element_text(angle=45,hjust=1,vjust=1),legend.text=element_text(size=5),legend.title=element_text(size=8),legend.key.size=unit(0.4,"cm"))

enter image description here

(由于我使用了plot.margin个参数,左侧会被切断,但我需要这个以下所示的内容。

然后根据深度截止值prunedendrogram以获得更少的聚类(即,只进行深度分割),并对生成的dendrogram进行一些编辑以获得它用他们想要的方式画出来:

depth.cutoff <- 11
dend <- cut(dend,h=depth.cutoff)$upper
require(dendextend)
gg.dend <- as.ggdend(dend)
leaf.heights <- dplyr::filter(gg.dend$nodes,!is.na(leaf))$height
leaf.seqments.idx <- which(gg.dend$segments$yend %in% leaf.heights)
gg.dend$segments$yend[leaf.seqments.idx] <- max(gg.dend$segments$yend[leaf.seqments.idx])
gg.dend$segments$col[leaf.seqments.idx] <- "black"
gg.dend$labels$label <- 1:nrow(gg.dend$labels)
gg.dend$labels$y <- max(gg.dend$segments$yend[leaf.seqments.idx])
gg.dend$labels$x <- gg.dend$segments$x[leaf.seqments.idx]
gg.dend$labels$col <- "black"
dend1.plot <- ggplot(gg.dend,labels=F)+scale_y_reverse()+coord_flip()+theme(plot.margin=unit(c(1,-3,1,1),"cm"))+annotate("text",size=5,hjust=0,x=gg.dend$label$x,y=gg.dend$label$y,label=gg.dend$label$label,colour=gg.dend$label$col)

enter image description here 我使用cowplot&#39; s plot_grid

将它们绘制在一起
require(cowplot)
plot_grid(dend1.plot,map1.plot,align='h',rel_widths=c(0.5,1))

enter image description here

虽然align='h'正在发挥作用但并不完美。

使用dendrogram使用map1.plot绘制未剪切的plot_grid说明了这一点:

dend0.plot <- ggplot(as.ggdend(dend))+scale_y_reverse()+coord_flip()+theme(plot.margin=unit(c(1,-1,1,1),"cm"))
plot_grid(dend0.plot,map1.plot,align='h',rel_widths=c(1,1))

enter image description here

dendrogram顶部和底部的树枝似乎朝向中心弯曲。使用scale似乎是一种调整它的方法,但是比例值似乎是针对特定数字的,所以我想知道是否有任何方法可以更有原则地做到这一点方式。

接下来,我对heatmap的每个群集进行一些术语丰富度分析。假设这个分析给了我data.frame

enrichment.df <- data.frame(term=rep(paste("t",1:10,sep=""),nrow(gg.dend$labels)),
                          cluster=c(sapply(1:nrow(gg.dend$labels),function(i) rep(i,5))),
                          score=rgamma(10*nrow(gg.dend$labels),0.2,0.7),
                          stringsAsFactors = F)

我想要做的是将此data.frame绘制为heatmap,并将剪切dendrogram放在其下方(类似于它放置在表达式heatmap)左侧。

所以我再次尝试plot_grid认为align='v'可以在这里工作:

首先重新生成树状图,使其面朝上:

dend2.plot <- ggplot(gg.dend,labels=F)+scale_y_reverse()+theme(plot.margin=unit(c(-3,1,1,1),"cm"))

现在尝试将它们联系在一起:

plot_grid(map2.plot,dend2.plot,align='v')

enter image description here

plot_grid似乎无法按照图中所示对齐它们并显示警告消息:

In align_plots(plotlist = plots, align = align) :
  Graphs cannot be vertically aligned. Placing graphs unaligned.

似乎接近的是:

plot_grid(map2.plot,dend2.plot,rel_heights=c(1,0.5),nrow=2,ncol=1,scale=c(1,0.675))

enter image description here

这是在使用scale参数后实现的,尽管情节太宽了。同样,我想知道是否有解决方法或以某种方式预先确定scaledendrogram的任何给定列表的正确heatmap是什么,也许是它们的尺寸。

2 个答案:

答案 0 :(得分:10)

我前段时间遇到了同样的问题。我使用的基本技巧是在给出树形图的结果的情况下直接指定基因的位置。为简单起见,首先是绘制完整树形图的情况:

# For the full dendrogram
library(plyr)
library(reshape2)
library(dplyr)
library(ggplot2)
library(ggdendro)
library(gridExtra)
library(dendextend)

set.seed(10)

# The source data
mat <- matrix(rnorm(24 * 10, mean = 1, sd = 2), 
              nrow = 24, ncol = 10, 
              dimnames = list(paste("g", 1:24, sep = ""), 
                              paste("sample", 1:10, sep = "")))

sample_names <- colnames(mat)

# Obtain the dendrogram
dend <- as.dendrogram(hclust(dist(mat)))
dend_data <- dendro_data(dend)

# Setup the data, so that the layout is inverted (this is more 
# "clear" than simply using coord_flip())
segment_data <- with(
    segment(dend_data), 
    data.frame(x = y, y = x, xend = yend, yend = xend))
# Use the dendrogram label data to position the gene labels
gene_pos_table <- with(
    dend_data$labels, 
    data.frame(y_center = x, gene = as.character(label), height = 1))

# Table to position the samples
sample_pos_table <- data.frame(sample = sample_names) %>%
    mutate(x_center = (1:n()), 
           width = 1)

# Neglecting the gap parameters
heatmap_data <- mat %>% 
    reshape2::melt(value.name = "expr", varnames = c("gene", "sample")) %>%
    left_join(gene_pos_table) %>%
    left_join(sample_pos_table)

# Limits for the vertical axes
gene_axis_limits <- with(
    gene_pos_table, 
    c(min(y_center - 0.5 * height), max(y_center + 0.5 * height))
) + 
    0.1 * c(-1, 1) # extra spacing: 0.1

# Heatmap plot
plt_hmap <- ggplot(heatmap_data, 
                   aes(x = x_center, y = y_center, fill = expr, 
                       height = height, width = width)) + 
    geom_tile() +
    scale_fill_gradient2("expr", high = "darkred", low = "darkblue") +
    scale_x_continuous(breaks = sample_pos_table$x_center, 
                       labels = sample_pos_table$sample, 
                       expand = c(0, 0)) + 
    # For the y axis, alternatively set the labels as: gene_position_table$gene
    scale_y_continuous(breaks = gene_pos_table[, "y_center"], 
                       labels = rep("", nrow(gene_pos_table)),
                       limits = gene_axis_limits, 
                       expand = c(0, 0)) + 
    labs(x = "Sample", y = "") +
    theme_bw() +
    theme(axis.text.x = element_text(size = rel(1), hjust = 1, angle = 45), 
          # margin: top, right, bottom, and left
          plot.margin = unit(c(1, 0.2, 0.2, -0.7), "cm"), 
          panel.grid.minor = element_blank())

# Dendrogram plot
plt_dendr <- ggplot(segment_data) + 
    geom_segment(aes(x = x, y = y, xend = xend, yend = yend)) + 
    scale_x_reverse(expand = c(0, 0.5)) + 
    scale_y_continuous(breaks = gene_pos_table$y_center, 
                       labels = gene_pos_table$gene, 
                       limits = gene_axis_limits, 
                       expand = c(0, 0)) + 
    labs(x = "Distance", y = "", colour = "", size = "") +
    theme_bw() + 
    theme(panel.grid.minor = element_blank())

library(cowplot)
plot_grid(plt_dendr, plt_hmap, align = 'h', rel_widths = c(1, 1))

Figure for the full dendrogram

请注意,我在热图图表的左侧保留了y轴刻度,只是为了表明树状图和刻度线完全匹配。

现在,对于切割树形图的情况,应该记住,树状图的叶子将不再以对应于给定簇中的基因的确切位置结束。为了获得基因和簇的位置,需要从切割完整的树形图中的两个树状图中提取数据。总的来说,为了澄清簇中的基因,我添加了划分簇的矩形。

# For the cut dendrogram
library(plyr)
library(reshape2)
library(dplyr)
library(ggplot2)
library(ggdendro)
library(gridExtra)
library(dendextend)

set.seed(10)

# The source data
mat <- matrix(rnorm(24 * 10, mean = 1, sd = 2), 
              nrow = 24, ncol = 10, 
              dimnames = list(paste("g", 1:24, sep = ""), 
                              paste("sample", 1:10, sep = "")))

sample_names <- colnames(mat)

# Obtain the dendrogram
full_dend <- as.dendrogram(hclust(dist(mat)))

# Cut the dendrogram
depth_cutoff <- 11
h_c_cut <- cut(full_dend, h = depth_cutoff)
dend_cut <- as.dendrogram(h_c_cut$upper)
dend_cut <- hang.dendrogram(dend_cut)
# Format to extend the branches (optional)
dend_cut <- hang.dendrogram(dend_cut, hang = -1) 
dend_data_cut <- dendro_data(dend_cut)

# Extract the names assigned to the clusters (e.g., "Branch 1", "Branch 2", ...)
cluster_names <- as.character(dend_data_cut$labels$label)
# Extract the names of the haplotypes that belong to each group (using
# the 'labels' function)
lst_genes_in_clusters <- h_c_cut$lower %>% 
    lapply(labels) %>% 
    setNames(cluster_names)

# Setup the data, so that the layout is inverted (this is more 
# "clear" than simply using coord_flip())
segment_data <- with(
    segment(dend_data_cut), 
    data.frame(x = y, y = x, xend = yend, yend = xend))

# Extract the positions of the clusters (by getting the positions of the 
# leafs); data is already in the same order as in the cluster name
cluster_positions <- segment_data[segment_data$xend == 0, "y"]
cluster_pos_table <- data.frame(y_position = cluster_positions, 
                                cluster = cluster_names)

# Specify the positions for the genes, accounting for the clusters
gene_pos_table <- lst_genes_in_clusters %>%
    ldply(function(ss) data.frame(gene = ss), .id = "cluster") %>%
    mutate(y_center = 1:nrow(.), 
           height = 1)
# > head(gene_pos_table, 3)
#    cluster gene y_center height
# 1 Branch 1  g11        1      1
# 2 Branch 1  g20        2      1
# 3 Branch 1  g12        3      1

# Table to position the samples
sample_pos_table <- data.frame(sample = sample_names) %>%
    mutate(x_center = 1:nrow(.), 
           width = 1)

# Coordinates for plotting rectangles delimiting the clusters: aggregate
# over the positions of the genes in each cluster
cluster_delim_table <- gene_pos_table %>%
    group_by(cluster) %>%
    summarize(y_min = min(y_center - 0.5 * height), 
              y_max = max(y_center + 0.5 * height)) %>%
    as.data.frame() %>%
    mutate(x_min = with(sample_pos_table, min(x_center - 0.5 * width)), 
           x_max = with(sample_pos_table, max(x_center + 0.5 * width)))

# Neglecting the gap parameters
heatmap_data <- mat %>% 
    reshape2::melt(value.name = "expr", varnames = c("gene", "sample")) %>%
    left_join(gene_pos_table) %>%
    left_join(sample_pos_table)

# Limits for the vertical axes (genes / clusters)
gene_axis_limits <- with(
    gene_pos_table, 
    c(min(y_center - 0.5 * height), max(y_center + 0.5 * height))
) + 
    0.1 * c(-1, 1) # extra spacing: 0.1

# Heatmap plot
plt_hmap <- ggplot(heatmap_data, 
                   aes(x = x_center, y = y_center, fill = expr, 
                       height = height, width = width)) + 
    geom_tile() +
    geom_rect(data = cluster_delim_table, 
              aes(xmin = x_min, xmax = x_max, ymin = y_min, ymax = y_max), 
              fill = NA, colour = "black", inherit.aes = FALSE) + 
    scale_fill_gradient2("expr", high = "darkred", low = "darkblue") +
    scale_x_continuous(breaks = sample_pos_table$x_center, 
                       labels = sample_pos_table$sample, 
                       expand = c(0.01, 0.01)) + 
    scale_y_continuous(breaks = gene_pos_table$y_center, 
                       labels = gene_pos_table$gene, 
                       limits = gene_axis_limits, 
                       expand = c(0, 0), 
                       position = "right") + 
    labs(x = "Sample", y = "") +
    theme_bw() +
    theme(axis.text.x = element_text(size = rel(1), hjust = 1, angle = 45), 
          # margin: top, right, bottom, and left
          plot.margin = unit(c(1, 0.2, 0.2, -0.1), "cm"), 
          panel.grid.minor = element_blank())

# Dendrogram plot
plt_dendr <- ggplot(segment_data) + 
    geom_segment(aes(x = x, y = y, xend = xend, yend = yend)) + 
    scale_x_reverse(expand = c(0, 0.5)) + 
    scale_y_continuous(breaks = cluster_pos_table$y_position, 
                       labels = cluster_pos_table$cluster, 
                       limits = gene_axis_limits, 
                       expand = c(0, 0)) + 
    labs(x = "Distance", y = "", colour = "", size = "") +
    theme_bw() + 
    theme(panel.grid.minor = element_blank())

library(cowplot)
plot_grid(plt_dendr, plt_hmap, align = 'h', rel_widths = c(1, 1.8))

Figure with the cut dendrogram

答案 1 :(得分:1)

这是一个基因和样本树状图的(暂定)解决方案。这是一个相当缺乏的解决方案,因为我没有设法找到一个好方法让plot_grid正确对齐所有子图,同时自动调整图比例和子图之间的距离。在这个版本中,产生整体数字的方法是添加&#34;填充子图&#34; (对plot_grid的调用中的侧翼NULL条目)以及手动微调子图的边缘(奇怪地看起来在各个子图中耦合)。再一次,这是一个相当缺乏的解决方案,希望我能尽快发布一个明确的版本。

library(plyr)
library(reshape2)
library(dplyr)
library(ggplot2)
library(ggdendro)
library(gridExtra)
library(dendextend)

set.seed(10)

# The source data
mat <- matrix(rnorm(24 * 10, mean = 1, sd = 2), 
              nrow = 24, ncol = 10, 
              dimnames = list(paste("g", 1:24, sep = ""), 
                              paste("sample", 1:10, sep = "")))

getDendrogram <- function(data_mat, depth_cutoff) {

    # Obtain the dendrogram
    full_dend <- as.dendrogram(hclust(dist(data_mat)))

    # Cut the dendrogram
    h_c_cut <- cut(full_dend, h = depth_cutoff)
    dend_cut <- as.dendrogram(h_c_cut$upper)
    dend_cut <- hang.dendrogram(dend_cut)
    # Format to extend the branches (optional)
    dend_cut <- hang.dendrogram(dend_cut, hang = -1) 
    dend_data_cut <- dendro_data(dend_cut)

    # Extract the names assigned to the clusters (e.g., "Branch 1", "Branch 2", ...)
    cluster_names <- as.character(dend_data_cut$labels$label)
    # Extract the entries that belong to each group (using the 'labels' function)
    lst_entries_in_clusters <- h_c_cut$lower %>% 
        lapply(labels) %>% 
        setNames(cluster_names)

    # The dendrogram data for plotting
    segment_data <- segment(dend_data_cut)

    # Extract the positions of the clusters (by getting the positions of the 
    # leafs); data is already in the same order as in the cluster name
    cluster_positions <- segment_data[segment_data$yend == 0, "x"]
    cluster_pos_table <- data.frame(position = cluster_positions, 
                                    cluster = cluster_names)

    list(
        full_dend = full_dend, 
        dend_data_cut = dend_data_cut, 

        lst_entries_in_clusters = lst_entries_in_clusters, 
        segment_data = segment_data, 
        cluster_pos_table = cluster_pos_table
    )
}

# Cut the dendrograms
gene_depth_cutoff <- 11
sample_depth_cutof <- 12

# Obtain the dendrograms
gene_dend_data <- getDendrogram(mat, gene_depth_cutoff)
sample_dend_data <- getDendrogram(t(mat), sample_depth_cutof)

# Specify the positions for the genes and samples, accounting for the clusters
gene_pos_table <- gene_dend_data$lst_entries_in_clusters %>%
    ldply(function(ss) data.frame(gene = ss), .id = "gene_cluster") %>%
    mutate(y_center = 1:nrow(.), 
           height = 1)
# > head(gene_pos_table, 3)
#    cluster gene y_center height
# 1 Branch 1  g11        1      1
# 2 Branch 1  g20        2      1
# 3 Branch 1  g12        3      1

# Specify the positions for the samples, accounting for the clusters
sample_pos_table <- sample_dend_data$lst_entries_in_clusters %>%
    ldply(function(ss) data.frame(sample = ss), .id = "sample_cluster") %>%
    mutate(x_center = 1:nrow(.), 
           width = 1)

# Neglecting the gap parameters
heatmap_data <- mat %>% 
    reshape2::melt(value.name = "expr", varnames = c("gene", "sample")) %>%
    left_join(gene_pos_table) %>%
    left_join(sample_pos_table)

# Limits for the vertical axes (genes / clusters)
axis_spacing <- 0.1 * c(-1, 1)
gene_axis_limits <- with(
    gene_pos_table, 
    c(min(y_center - 0.5 * height), max(y_center + 0.5 * height))) + axis_spacing

sample_axis_limits <- with(
    sample_pos_table, 
    c(min(x_center - 0.5 * width), max(x_center + 0.5 * width))) + axis_spacing

# For some reason, the margin of the various sub-plots end up being "coupled"; 
# therefore, for now this requires some manual fine-tuning, 
# which is obviously not ideal...
# margin: top, right, bottom, and left
margin_specs_hmap <- 1 * c(-2, -1, -1, -2)
margin_specs_gene_dendr <- 1.7 * c(-1, -2, -1, -1)
margin_specs_sample_dendr <- 1.7 * c(-2, -1, -2, -1)

# Heatmap plot
plt_hmap <- ggplot(heatmap_data, 
                   aes(x = x_center, y = y_center, fill = expr, 
                       height = height, width = width)) + 
    geom_tile() +
    scale_fill_gradient2("expr", high = "darkred", low = "darkblue") +
    scale_x_continuous(breaks = sample_pos_table$x_center, 
                       labels = sample_pos_table$sample, 
                       expand = c(0.01, 0.01)) + 
    scale_y_continuous(breaks = gene_pos_table$y_center, 
                       labels = gene_pos_table$gene, 
                       limits = gene_axis_limits, 
                       expand = c(0.01, 0.01), 
                       position = "right") + 
    labs(x = "Sample", y = "Gene") +
    theme_bw() +
    theme(axis.text.x = element_text(size = rel(1), hjust = 1, angle = 45), 
          axis.text.y = element_text(size = rel(0.7)), 
          legend.position = "none", 
          plot.margin = unit(margin_specs_hmap, "cm"), 
          panel.grid.minor = element_blank())

# Dendrogram plots
plt_gene_dendr <- ggplot(gene_dend_data$segment_data) + 
    geom_segment(aes(x = y, y = x, xend = yend, yend = xend)) + # inverted coordinates
    scale_x_reverse(expand = c(0, 0.5)) + 
    scale_y_continuous(breaks = gene_dend_data$cluster_pos_table$position, 
                       labels = gene_dend_data$cluster_pos_table$cluster, 
                       limits = gene_axis_limits, 
                       expand = c(0, 0)) + 
    labs(x = "Distance", y = "", colour = "", size = "") +
    theme_bw() + 
    theme(plot.margin = unit(margin_specs_gene_dendr, "cm"), 
          panel.grid.minor = element_blank())

plt_sample_dendr <- ggplot(sample_dend_data$segment_data) + 
    geom_segment(aes(x = x, y = y, xend = xend, yend = yend)) + 
    scale_y_continuous(expand = c(0, 0.5), 
                       position = "right") + 
    scale_x_continuous(breaks = sample_dend_data$cluster_pos_table$position, 
                       labels = sample_dend_data$cluster_pos_table$cluster, 
                       limits = sample_axis_limits, 
                       position = "top", 
                       expand = c(0, 0)) + 
    labs(x = "", y = "Distance", colour = "", size = "") +
    theme_bw() + 
    theme(plot.margin = unit(margin_specs_sample_dendr, "cm"), 
          panel.grid.minor = element_blank(), 
          axis.text.x = element_text(size = rel(0.8), angle = 45, hjust = 0))

library(cowplot)

final_plot <- plot_grid(
    NULL,    NULL,           NULL,             NULL, 
    NULL,    NULL,           plt_sample_dendr, NULL, 
    NULL,    plt_gene_dendr, plt_hmap,         NULL, 
    NULL,    NULL,           NULL,             NULL, 
    nrow = 4, ncol = 4, align = "hv", 
    rel_heights = c(0.5, 1, 2, 0.5), 
    rel_widths = c(0.5, 1, 2, 0.5)
)

Figure with both the gene and sample dendrograms