Retrieve Clusters From ComplexHeatmap

Question

[pthom010]

I made a heatmap with the following data (the actual table has 240 rows):

tf.log


                              0-dpi      1-dpi     7-dpi    14-dpi      22-dpi
TRINITY_DN0_c0_g1_i2      1.27584408  0.5872404  1.780178  1.414362  1.53341851
TRINITY_DN10214_c0_g1_i2 -2.34774378 -2.9194079 -3.211677 -2.885869 -2.04617227
TRINITY_DN10214_c0_g1_i6 -2.14867876 -1.5794957 -1.577811 -2.485095 -1.44172768
TRINITY_DN1038_c0_g1_i4   0.03163921  0.7375222  2.037936  2.462830  0.04559793
TRINITY_DN10462_c0_g1_i2 -2.63973533 -2.8039350 -2.481144 -2.698932 -1.76284020
TRINITY_DN1052_c0_g1_i3  -3.32767605 -2.2006082 -1.887869 -1.211592 -1.43292669

I then made the following heatmap:

heat.gen.k = Heatmap(tf.log, width = unit(10, "cm"),
                     km = 12, 
                     cluster_columns = F, 
                     show_row_names = F, 
                     row_title_rot = 0, 
                     row_gap = unit(3, "mm"), 
                     name = "Log2FC", 
                     column_title = "Resistant - Susceptible",
                     column_title_gp = gpar(fontfamily = "sans", fontsize = 28), 
                     column_names_gp = gpar(fontfamily = "sans", fontsize = 20),
                     col = heat.col,
                     right_annotation = ha)
print(heat.gen.k)

I would like to pull the clusters out for downstream analysis but I cannot do so with the following code:

clusterlist = row_order(heat.gen.k)
clu_df <- lapply(names(clusterlist), function(i){
  out <- data.frame(GeneID = rownames(tf.log[clusterlist[[i]],]),
                                             Cluster = paste0("cluster", i),
                                             stringsAsFactors = FALSE)
     return(out)
   }) %>%  
     do.call(rbind, .)

I keep getting the following error:

Error in data.frame(GeneID = rownames(tf.log[clusterlist[[i]], ]), Cluster = paste0("cluster",  :
  arguments imply differing number of rows: 0, 1

Not sure how to resolve this issue.

Answer 1

[ATpoint]

It happens when a cluster consists of only one gene. In that case you are extracting a data.frame with a single row and this is then coerced into a vector which has no rownames. You can easily avoid that by changing:

rownames(tf.log[clusterlist[[i]],]) into rownames(tf.log)[clusterlist[[i]]] so you don't extract the data.frame and then the rownames but extract the rownames first and then subset it to those genes you have per cluster.

[pthom010]

This worked. Thanks!