Skill: Multiple Volcano Plot (R)

Category

Omics

When to Use

Multiple Volcano Plot is a graph used for differential expression analysis of high-throughput data (such as transcriptomes and proteomes). Compared with the traditional volcano plot, the multi-group volcano plot can display the results of multiple groups at the same time, making it easier to compare the consistency or specificity of differential features horizontally.

Required R Packages

• corrplot
• scRNAtoolVis

Minimal Reproducible Code

# Load packages
library(corrplot)
library(scRNAtoolVis)

# Prepare data
# Load data
data('pbmc.markers')
# View data
head(pbmc.markers)

# Create visualization
# Basic Multiple Volcano Plot
p <- jjVolcano(
  diffData = pbmc.markers,
  topGeneN = 5,
  log2FC.cutoff = 0.5,
  col.type = "updown",
  aesCol = c('#0099CC','#CC3333'),
  tile.col = corrplot::COL2('PuOr', 15)[4:12],
  cluster.order = rev(unique(pbmc.markers$cluster)),
  size  = 3.5,
  fontface = 'italic'
  )

p

Key Parameters

• position: Position adjustment (identity, dodge, stack, fill)
• fill: Maps a variable to fill color for group comparison
• color: Maps a variable to outline/point color

Tips

• Adjust text size with theme(text = element_text(size = 14)) for presentations
• Include appropriate statistical thresholds (e.g., FDR < 0.05, |log2FC| > 1) in the visualization
• See the full tutorial for additional customization options and advanced examples

Full Tutorial

https://openbiox.github.io/Bizard/Omics/MultiVolcanoPlot.html