Description
Return factor ln(sourceBase)/ln(targetBase) and value multiplied by it.
Information units depend on the logarithm base: base two gives bits and the natural logarithm gives nats. A derivative or conversion factor must preserve its stated variable and base.
Return factor ln(sourceBase)/ln(targetBase) and value multiplied by it.
When to use this tool
Use Surprisal Base Change Factor when you need an explicit information-unit conversion or surprisal component.
How to use the tool and how it works
- Enter value, sourceBase, targetBase. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read value, factor. Use the output convention below.
Require positive source and target bases different from one. Return factor ln(sourceBase)/ln(targetBase) and value multiplied by it.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| value | Value | Required. Finite number. |
| sourceBase | Source logarithm base for the supplied information value. | Required. Finite number; strictly above 0. |
| targetBase | Target logarithm base for the converted information value. | Required. Finite number; strictly above 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| value | Value | Required. Finite number. |
| factor | Factor | Required. Finite number. |
{
"input": {
"value": 3,
"sourceBase": 2,
"targetBase": 4
},
"output": {
"value": 1.5,
"factor": 0.5
}
}Limitations and assumptions
- Bases below one and signed values are allowed; these may reverse the conventional positive-information interpretation.
- 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
Check the probability domain and logarithm convention of the complete measure before combining values.
References
Similar or alternative tools
- Information: Surprisal Log Base Crosswalk
Multiply nonnegative surprisal by ln(sourceBase)/ln(targetBase), requiring both bases greater than one.
- Entropy Base Ratio
Return ln(sourceBase)/ln(targetBase) for positive bases different from one.