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Surprisal Concentration Weight Term Tool

One explicitly weighted surprisal term, without assuming the weight equals the event probability.

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Description

Return -ln(probability)/ln(logBase) and multiply it by nonnegative weight for weightedTerm.

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 -ln(probability)/ln(logBase) and multiply it by nonnegative weight for weightedTerm.

When to use this tool

Use Surprisal Concentration Weight Term when you need an explicit information-unit conversion or surprisal component.

How to use the tool and how it works

  1. Enter probability, weight, logBase. Use the units and conventions below.
  2. Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
  3. Read surprisal, weightedTerm. Use the output convention below.

Return -ln(probability)/ln(logBase) and multiply it by nonnegative weight for weightedTerm. Require probability in (0, 1] and logBase > 1.1

Input fieldMeaning and unitsAccepted input
probabilityProbability in the stated interval; zero handling follows the calculation above.Required. Finite number; maximum 1; strictly above 0.
weightWeightRequired. Finite number; minimum 0.
logBaseLogarithm base; base 2 gives bits and base e gives nats under conventional bases greater than one.Required. Finite number; strictly above 1.
Output fieldInterpretationReturned shape
surprisalInformation value in the specified logarithm-base units.Required. Finite number.
weightedTermWeighted TermRequired. Finite number.
json
{
  "input": {
    "probability": 0.25,
    "weight": 0.5,
    "logBase": 2
  },
  "output": {
    "surprisal": 2,
    "weightedTerm": 1
  }
}

Limitations and assumptions

  • Weight is an explicit multiplier rather than automatically a probability mass; this is one term without aggregate normalization.
  • 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

  1. Calculation and input contract: information/surprisal-concentration-weight-term — tool.io

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