Module:RiskRange/doc

This is the documentation page for Module:RiskRange

This module converts two probability values into a human-friendly range string with a common denominator, making it easy to compare the low and high estimates.

Usage

From wikitext (via Template:RiskRange):

{{RiskRange|probability1|probability2}}

Direct module invocation:

{{#invoke:RiskRange|convert|probability1|probability2}}

Parameters

Parameter	Description
`1`	First probability (decimal between 0 and 1)
`2`	Second probability (decimal between 0 and 1)

The module automatically orders the probabilities so the lower risk appears first and higher risk appears second.

Output Format

The module outputs ranges in the format "N to M in D" where:

N = lower numerator (lower risk)
M = higher numerator (higher risk)
D = common denominator

Denominator Selection

If either probability is ≥ 0.1, the denominator is 10 (e.g., "2 to 6 in 10")
Otherwise, the denominator is chosen based on the smaller probability, rounded to a "nice" value (10, 20, 50, 100, 200, 500, 1,000, etc.)

Special Cases

Condition	Output
Both probabilities ≤ 0	"no chance"
Both probabilities ≥ 1	"100% chance"
Both probabilities ≥ 0.95	"almost certain"
One is 0, other is 1	"anywhere from no chance to certain"
Probabilities within 5% of each other	Single value, e.g., "about 5 in 10"
Lower probability ≈ 0	"up to about N in D"
Higher probability ≥ 1	"at least N in D"

Examples

Input	Output
`{{RiskRange\|0.2\|0.6}}`	2 to 6 in 10
`{{RiskRange\|0.001\|0.01}}`	1 to 10 in 1,000
`{{RiskRange\|0.21\|0.6}}`	2 to 6 in 10
`{{RiskRange\|0.33\|0.82}}`	3 to 8 in 10
`{{RiskRange\|0.01\|0.05}}`	1 to 5 in 100
`{{RiskRange\|0.0001\|0.001}}`	1 to 10 in 10,000
`{{RiskRange\|0.5\|0.5}}`	about 5 in 10
`{{RiskRange\|0\|0.5}}`	up to about 5 in 10

Algorithm

Validate inputs and handle error cases
Order probabilities (lower first)
Check for special cases (zero, one, equal, almost certain)
Select common denominator:
- Use 10 if higher probability ≥ 0.1
- Otherwise use nice_denominator(1/lower_probability)
Calculate numerators: N = probability × denominator
Round numerators to integers
If both round to same value, try larger denominator
Format output string