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  2. Cross-entropy - Wikipedia

    en.wikipedia.org/wiki/Cross-entropy

    This is also known as the log loss (or logarithmic loss [4] or logistic loss); [5] the terms "log loss" and "cross-entropy loss" are used interchangeably. [ 6 ] More specifically, consider a binary regression model which can be used to classify observations into two possible classes (often simply labelled 0 {\displaystyle 0} and 1 ...

  3. Loss functions for classification - Wikipedia

    en.wikipedia.org/wiki/Loss_functions_for...

    Given the binary nature of classification, a natural selection for a loss function (assuming equal cost for false positives and false negatives) would be the 0-1 loss function (0–1 indicator function), which takes the value of 0 if the predicted classification equals that of the true class or a 1 if the predicted classification does not match ...

  4. Kullback–Leibler divergence - Wikipedia

    en.wikipedia.org/wiki/Kullback–Leibler_divergence

    The entropy () thus sets a minimum value for the cross-entropy (,), the expected number of bits required when using a code based on Q rather than P; and the Kullback–Leibler divergence therefore represents the expected number of extra bits that must be transmitted to identify a value x drawn from X, if a code is used corresponding to the ...

  5. Entropy (information theory) - Wikipedia

    en.wikipedia.org/wiki/Entropy_(information_theory)

    Entropy (thermodynamics) Cross entropy – is a measure of the average number of bits needed to identify an event from a set of possibilities between two probability distributions; Entropy (arrow of time) Entropy encoding – a coding scheme that assigns codes to symbols so as to match code lengths with the probabilities of the symbols. Entropy ...

  6. Cross-entropy method - Wikipedia

    en.wikipedia.org/wiki/Cross-Entropy_Method

    The cross-entropy (CE) method is a Monte Carlo method for importance sampling and optimization. It is applicable to both combinatorial and continuous problems, with either a static or noisy objective. The method approximates the optimal importance sampling estimator by repeating two phases: [1] Draw a sample from a probability distribution.

  7. Multinomial logistic regression - Wikipedia

    en.wikipedia.org/wiki/Multinomial_logistic...

    In particular, learning in a naive Bayes classifier is a simple matter of counting up the number of co-occurrences of features and classes, while in a maximum entropy classifier the weights, which are typically maximized using maximum a posteriori (MAP) estimation, must be learned using an iterative procedure; see #Estimating the coefficients.

  8. Spin crossover - Wikipedia

    en.wikipedia.org/wiki/Spin_crossover

    Structures of tris(2-picolylamine)Fe(II) in two spin states. [8]Due to the changes in magnetic properties that occur from a spin transition - the complex being less magnetic in a LS state and more magnetic in a HS state - magnetic susceptibility measurements are key to characterization of spin crossover compounds.

  9. Mutual information - Wikipedia

    en.wikipedia.org/wiki/Mutual_information

    The joint information is equal to the mutual information plus the sum of all the marginal information (negative of the marginal entropies) for each particle coordinate. Boltzmann's assumption amounts to ignoring the mutual information in the calculation of entropy, which yields the thermodynamic entropy (divided by the Boltzmann constant).