Hi,

I was using the pheatmap to cluster all the samples and do the visualization, but i was confused that how to increase the size legend which shows like that. 

Thank you so much.

<a href="https://ibb.co/iwBM3z"><img src="https://preview.ibb.co/mXEKqe/Snipaste_2018_08_03_15_39_23.png" alt="Snipaste 2018 08 03 15 39 23" border="0" /></a>
Take a back up of your code posted above, and try plotting with this basic code (OP code). If you can see the legend, then keep optimizing heatmap. I think unoptimized cell and other parameters are issue here in code (as data is not furnished) :

    pheatmap(data,
             method = c("pearson"),
             clustering_method = "complete",
             treeheight_row = 40,
             treeheight_col = 40,
             cluster_row = T,
             cluster_col = T,
             show_rownames = T,
             show_colnames = T,
             legend = T,
             fontsize = 10,
             color = colorRampPalette(brewer.pal(9,"Reds"))(400))

