validate_allele_freq: Validate Allele Frequency Input

In penetrance: Methods for Penetrance Estimation in Family-Based Studies

Validate Allele Frequency Input

Description

This function validates whether the provided input is a valid allele frequency. Allele frequencies must be numeric, scalar, and within the range ⁠[0, 1]⁠. The function also provides warnings for edge cases and common mistakes.

Usage

validate_allele_freq(
  allele_freq,
  param_name = "allele_freq",
  warn_threshold = 0.01
)

Arguments

allele_freq	The allele frequency value to validate. Should be a numeric value between 0 and 1.
param_name	Character string specifying the parameter name (for error messages). Default is "allele_freq".
warn_threshold	Numeric value above which to issue a warning about unusually high allele frequency. Default is 0.01 (1%).

Details

The function checks:

• Whether the input is numeric

• Whether the input is a single value (not a vector)

• Whether the value is between 0 and 1 (inclusive)

• Whether the value is unusually high (> warn_threshold), which may indicate the user provided carrier prevalence instead of allele frequency

• Whether the value is exactly 0 or 1, which may not be biologically meaningful

Value

Logical value TRUE if the allele frequency is valid (with possible warnings), otherwise stops with an error message.

Examples

# Valid allele frequencies
validate_allele_freq(0.0001) # Common for rare variants
validate_allele_freq(0.001)
validate_allele_freq(0.05)

## Not run: 
# Invalid inputs (will throw errors)
validate_allele_freq("0.001")          # Not numeric
validate_allele_freq(c(0.001, 0.002))  # Vector instead of scalar
validate_allele_freq(-0.001)           # Negative value
validate_allele_freq(1.5)              # Greater than 1
validate_allele_freq(NA)               # Missing value

# Valid but will trigger warnings
validate_allele_freq(0.02)         # Unusually high (>1%), warning
validate_allele_freq(0)            # Edge case, warning
validate_allele_freq(1)            # Edge case, warning

## End(Not run)

penetrance documentation built on Sept. 9, 2026, 1:07 a.m.