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Binary Entropy Curvature Term Tool

Return Bernoulli entropy’s second derivative under an explicit logarithm base, without computing entropy itself.

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Description

Return -1/[probability × (1 - probability) × ln(logBase)].

Entropy summarizes uncertainty under a specified probability model and logarithm convention. Support indicators, one-symbol terms, and exponentiated entropies are components with different meanings.

Return -1/[probability × (1 - probability) × ln(logBase)].

When to use this tool

Use Binary Entropy Curvature Term when you need one explicitly scoped entropy or support calculation.

How to use the tool and how it works

  1. Enter probability, 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 curvature. Use the output convention below.

Require probability in (0, 1) and positive logBase different from one. Return -1/[probability × (1 - probability) × ln(logBase)].1

Input fieldMeaning and unitsAccepted input
probabilityProbability in the stated interval; zero handling follows the calculation above.Required. Finite number; strictly above 0; strictly below 1.
logBaseLogarithm base; base 2 gives bits and base e gives nats under conventional bases greater than one.Required. Finite number; strictly above 0.
Output fieldInterpretationReturned shape
curvatureCurvatureRequired. Finite number.
json
{
  "input": {
    "probability": 0.5,
    "logBase": 2.718281828459045
  },
  "output": {
    "curvature": -4
  }
}

Limitations and assumptions

  • Bases below one reverse the usual curvature sign; this is a derivative term rather than an entropy estimate.
  • 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

Validate and align complete probability distributions before aggregating terms or interpreting an uncertainty estimate.

References

  1. Calculation and input contract: information/binary-entropy-curvature-term — tool.io

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