Description
Multiply nonnegative surprisal by ln(sourceBase)/ln(targetBase), requiring both bases greater than one.
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.
Multiply nonnegative surprisal by ln(sourceBase)/ln(targetBase), requiring both bases greater than one.
When to use this tool
Use Information: Surprisal Log Base Crosswalk when you need an explicit information-unit conversion or surprisal component.
How to use the tool and how it works
- Enter surprisal, 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 result. Expand result to inspect the returned fields.
Multiply nonnegative surprisal by ln(sourceBase)/ln(targetBase), requiring both bases greater than one.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| surprisal | Information value in the specified logarithm-base units. | Required. Finite number. |
| sourceBase | Source logarithm base for the supplied information value. | Required. Finite number. |
| targetBase | Target logarithm base for the converted information value. | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| result | Result | Required. Object. |
| result.surprisal | Information value in the specified logarithm-base units. | Calculated result member: number. |
{
"input": {
"surprisal": 3,
"sourceBase": 2,
"targetBase": 8
},
"output": {
"result": {
"surprisal": 1
}
}
}Limitations and assumptions
- Base two gives bits and base e nats; this changes units without checking the probability that produced the supplied surprisal.
- Outputs are nested inside result. 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
- Surprisal Base Change Factor
Return factor ln(sourceBase)/ln(targetBase) and value multiplied by it.
- Entropy Base Ratio
Return ln(sourceBase)/ln(targetBase) for positive bases different from one.