Description
Divide by sites when positive, otherwise return zero with defined false.
Sequence-derived quantities depend on aligned observations, callable sites and a stated substitution or codon model. A count ratio or one site's opportunity is distinct from a corrected evolutionary distance or statistical evidence of selection.
Divide by sites when positive, otherwise return zero with defined false.
When to use this tool
Use Codon Sites Zero Denominator when you need the stated sequence-distance or codon-opportunity term.
How to use the tool and how it works
- Enter changes, sites. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read defined, changesPerSite. Inspect defined before interpreting the associated values.
Require nonnegative integer changes and nonnegative sites. Divide by sites when positive, otherwise return zero with defined false.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| changes | Changes | Required. Safe integer; minimum 0. |
| sites | Sites | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| defined | Whether the stated denominator or normalization exists; inspect before interpreting a zero placeholder. | Required. Boolean. |
| changesPerSite | Changes Per Site | Required. Finite number. |
{
"input": {
"changes": 0,
"sites": 0
},
"output": {
"defined": false,
"changesPerSite": 0
}
}Limitations and assumptions
- The zero placeholder is not a measured zero rate. Counts/site opportunities are supplied rather than derived from sequence or corrected for multiple substitutions.
- 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
Use a complete sequence-analysis method with an appropriate alignment, genetic code and model. Review gaps, missingness, multiple substitutions, saturation and uncertainty before biological interpretation.
References
Similar or alternative tools
- dN/dS One Codon Site Count Term
Return change/site dN and dS and their ratio.
- Codon Site Opportunity Share
Sum callable opportunities and selected callable opportunity; divide or return flagged zero.