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  2. NaN - Wikipedia

    en.wikipedia.org/wiki/NaN

    In section 6.2 of the old IEEE 754-2008 standard, there are two anomalous functions (the maxNum and minNum functions, which return the maximum and the minimum, respectively, of two operands that are expected to be numbers) that favor numbers — if just one of the operands is a NaN then the value of the other operand is returned.

  3. Missing data - Wikipedia

    en.wikipedia.org/wiki/Missing_data

    Values in a data set are missing completely at random (MCAR) if the events that lead to any particular data-item being missing are independent both of observable variables and of unobservable parameters of interest, and occur entirely at random. [5] When data are MCAR, the analysis performed on the data is unbiased; however, data are rarely MCAR.

  4. Contingency table - Wikipedia

    en.wikipedia.org/wiki/Contingency_table

    The example above is the simplest kind of contingency table, a table in which each variable has only two levels; this is called a 2 × 2 contingency table. In principle, any number of rows and columns may be used. There may also be more than two variables, but higher order contingency tables are difficult to represent visually.

  5. IEEE 754 - Wikipedia

    en.wikipedia.org/wiki/IEEE_754

    In general, NaNs will be propagated, i.e. most operations involving a NaN will result in a NaN, although functions that would give some defined result for any given floating-point value will do so for NaNs as well, e.g. NaN ^ 0 = 1. There are two kinds of NaNs: the default quiet NaNs and, optionally, signaling NaNs.

  6. Dickey–Fuller test - Wikipedia

    en.wikipedia.org/wiki/Dickey–Fuller_test

    Each version of the test has its own critical value which depends on the size of the sample. In each case, the null hypothesis is that there is a unit root, δ = 0 {\displaystyle \delta =0} . The tests have low statistical power in that they often cannot distinguish between true unit-root processes ( δ = 0 {\displaystyle \delta =0} ) and near ...

  7. Comparison of numerical-analysis software - Wikipedia

    en.wikipedia.org/wiki/Comparison_of_numerical...

    MATLAB: MathWorks: late 1970s 1984 9.12 (R2022a) 15 March 2022: $2150 (standard), $500 (education), $149 (home), $49 (student) Proprietary: Numerical computation and simulation with extended 2D/3D visualization. Emphasis on vectorised processing. Maxima: MIT Project MAC and Bill Schelter et al. 1967 1982 5.47.0 31 May 2023: Free GPL: Mainly a ...

  8. Confusion matrix - Wikipedia

    en.wikipedia.org/wiki/Confusion_matrix

    Confusion matrix is not limited to binary classification and can be used in multi-class classifiers as well. The confusion matrices discussed above have only two conditions: positive and negative. For example, the table below summarizes communication of a whistled language between two speakers, with zero values omitted for clarity. [20]

  9. Nonparametric statistics - Wikipedia

    en.wikipedia.org/wiki/Nonparametric_statistics

    Mann–Whitney U or Wilcoxon rank sum test: tests whether two samples are drawn from the same distribution, as compared to a given alternative hypothesis. McNemar's test: tests whether, in 2 × 2 contingency tables with a dichotomous trait and matched pairs of subjects, row and column marginal frequencies are equal.