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Generate a volcano plot for a comparison in a VISTA object

get_volcano_plot.Rd

Wraps EnhancedVolcano to visualize log2FC vs p-values for a selected comparison.

Usage

get_volcano_plot(
  x,
  sample_comparison,
  log2fc_cutoff = 1,
  pval_cutoff = 0.05,
  genes_to_display = NULL,
  lab_size = 3,
  point_size = 1,
  col_up = "#a40000",
  col_down = "#007e2f",
  col_other = "grey",
  repair_genes = TRUE,
  display_id = NULL,
  display_from = NULL,
  display_orgdb = NULL,
  ...
)

Arguments

x

A VISTA object containing differential expression results.

sample_comparison

Character scalar naming the comparison to display.

log2fc_cutoff

Numeric absolute log2 fold-change threshold used to color significant points.

pval_cutoff

Numeric p-value threshold used to color significant points.

genes_to_display

Optional character vector of gene identifiers to force-label.

lab_size

Numeric label text size.

point_size

Numeric point size.

col_up

Color assigned to up-regulated genes.

col_down

Color assigned to down-regulated genes.

col_other

Color assigned to non-significant genes.

repair_genes

Logical; when TRUE, split gene_id values like ID:SYMBOL to display the symbol.

display_id

Optional ID/column name to use for plot labels. If supplied and present in rowData(x), those values are used; otherwise falls back to ID mapping.

display_from

Optional source ID type for mapping (used when display_id is not found in rowData).

display_orgdb

Optional OrgDb object used for ID mapping when display_id is set but not found in rowData.

...

Additional parameters forwarded to EnhancedVolcano::EnhancedVolcano().

Examples

if (FALSE) { # \dontrun{
# Create VISTA object
data("count_data", package = "VISTA")
data("sample_metadata", package = "VISTA")

vista <- create_vista(
  counts = count_data,
  sample_info = sample_metadata,
  column_geneid = "gene_id",
  group_column = "cond_long",
  group_numerator = "treatment1",
  group_denominator = "control"
)

# Basic volcano plot
comps <- names(comparisons(vista))
get_volcano_plot(vista, sample_comparison = comps[1])

# With custom thresholds
get_volcano_plot(
  vista,
  sample_comparison = comps[1],
  log2fc_cutoff = 1.5,
  pval_cutoff = 0.01
)

# Highlight specific genes
genes_of_interest <- rownames(vista)[1:5]
get_volcano_plot(
  vista,
  sample_comparison = comps[1],
  genes_to_display = genes_of_interest
)
} # }