How to zoom in on sections of a heatmap using pheatmap package in R

Question

[Rex]

Hi everyone! I generated a heatmap of some single cell data (3285 cells x 6000 genes) using the pheatmap package on Rstudio. The columns are different individual cells, and the rows are different genes. I was able to find a pattern looking at the heatmap, and now I want to take a closer look at those sections. Is there anyway I could zoom in onto the regions of the heatmap squared in yellow other than just zooming in on the picture?

Thank you so much!

[seidel]

One way to isolate sections is to navigate the dendrogram. You can cut it into clusters, one of which will contain your pattern. However, if your data is so dense you can't even see the dendrogram to evaluate it, one method I would suggest would be to down sample your data so that you can at least see the patterns in it. When you have hundreds of genes (or whatever) making up clusters, you don't need all of them in there to see that pattern. You can expect a robust pattern to persist with fractional amounts of data. Once you find genes in the cluster of interest, you can always go back in and pull out the closest X genes to that pattern.