Convert p-values to significance labels

Converts numeric p-values into categorical significance labels according to user-defined thresholds. The function is commonly used to annotate statistical results in tables and figures.

Usage

pval2asterisk(
  x,
  break_points = c(0.055, 0.05, 0.01, 0.001, 0),
  symbols = c("ns", ".", "*", "**", "***")
)

Arguments

x

A numeric vector of p-values.

break_points

A numeric vector of significance thresholds in descending order. Each threshold defines the upper bound of a significance interval. The default values correspond to:

• \(p > 0.055\): "ns"

• \(0.05 < p \le 0.055\): "."

• \(0.01 < p \le 0.05\): "*"

• \(0.001 < p \le 0.01\): "**"

• \(p \le 0.001\): "***"

symbols

A character vector of significance labels corresponding to break_points. The lengths of break_points and symbols must be identical.

Value

A character vector of the same length as x, where each element is the corresponding significance label.

Details

Each p-value is assigned to exactly one interval defined by break_points. Values greater than the first threshold are assigned symbols[1], whereas values less than or equal to the last threshold are assigned the last element of symbols. Intermediate intervals are matched sequentially.

The function assumes that break_points are supplied in descending order.

Examples

p <- c(0.20, 0.04, 0.008, 0.0005, 1e-6)
pval2asterisk(p)
#> [1] "ns"  "*"   "**"  "***" "***"

# Custom significance labels
pval2asterisk(
  p,
  break_points = c(0.05, 0.01, 0),
  symbols = c("Not significant", "Significant", "Highly significant")
)
#> [1] "Not significant"    "Significant"        "Highly significant"
#> [4] "Highly significant" "Highly significant"