Description
Invert an ordered ratio interval that excludes zero.
Proportions depend on the order of a ratio, its denominator and whether an input is a decimal fraction or a percentage number. Inverting a zero-crossing interval is undefined, and rounding an ideal share to a quantum can exceed a total. Supplied conservation, tax or mixing assumptions need explicit units and boundaries before interpretation.
Invert an ordered ratio interval that excludes zero.
When to use this tool
Use Ratio Inversion Interval Endpoints when you already have lowerRatio, upperRatio and need to invert an ordered ratio interval that excludes zero.
How to use the tool and how it works
- Enter lowerRatio, upperRatio. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read inverseLower, inverseUpper. Use the output convention below.
Require lower<=upper and either lower>0 or upper<0; return 1/upper as inverseLower and 1/lower as inverseUpper.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| lowerRatio | Lower Ratio | Required. Finite number. |
| upperRatio | Upper Ratio | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| inverseLower | 1/upperRatio; interval inversion reverses endpoint order. | Required. Finite number. |
| inverseUpper | Inverse Upper | Required. Finite number. |
{
"input": {
"lowerRatio": 2,
"upperRatio": 4
},
"output": {
"inverseLower": 0.25,
"inverseUpper": 0.5
}
}Limitations and assumptions
- Both positive and wholly negative intervals are accepted; crossing or touching zero is rejected and no uncertainty model is inferred.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Write the numerator, denominator and ratio direction explicitly before rebasing or inverting a quantity. Use a full allocation or mass balance for multiple components, and account for quantum remainders jointly when rounded shares must add to a fixed total.
References
Similar or alternative tools
- Weighted Share Denominator Rebase
Compare one weighted numerator under two positive denominators.
- Target Ratio Missing Part
Calculate a missing ratio part from a known part and known-to-missing ratio.