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  2. Online analytical processing - Wikipedia

    en.wikipedia.org/wiki/Online_analytical_processing

    For example, the overall sum of a roll-up is just the sum of the sub-sums in each cell. Functions that can be decomposed in this way are called decomposable aggregation functions, and include COUNT, MAX, MIN, and SUM, which can be computed for each cell and then directly aggregated; these are known as self-decomposable aggregation functions. [13]

  3. Comma-separated values - Wikipedia

    en.wikipedia.org/wiki/Comma-separated_values

    The CSV file format is one type of delimiter-separated file format. [2] Delimiters frequently used include the comma, tab, space, and semicolon. Delimiter-separated files are often given a ".csv" extension even when the field separator is not a comma. Many applications or libraries that consume or produce CSV files have options to specify an ...

  4. Sparse matrix - Wikipedia

    en.wikipedia.org/wiki/Sparse_matrix

    The old Yale format works exactly as described above, with three arrays; the new format combines ROW_INDEX and COL_INDEX into a single array and handles the diagonal of the matrix separately. [ 9 ] For logical adjacency matrices , the data array can be omitted, as the existence of an entry in the row array is sufficient to model a binary ...

  5. Contingency table - Wikipedia

    en.wikipedia.org/wiki/Contingency_table

    Then its sign equals the sign of the product of the main diagonal elements of the table minus the product of the off–diagonal elements. φ takes on the minimum value −1.0 or the maximum value of +1.0 if and only if every marginal proportion is equal to 0.5 (and two diagonal cells are empty). [2]

  6. PageRank - Wikipedia

    en.wikipedia.org/wiki/PageRank

    The adjacency function is 0 if page does not link to , and normalized such that, for each j ∑ i = 1 N ℓ ( p i , p j ) = 1 {\displaystyle \sum _{i=1}^{N}\ell (p_{i},p_{j})=1} , i.e. the elements of each column sum up to 1, so the matrix is a stochastic matrix (for more details see the computation section below).

  7. Spearman's rank correlation coefficient - Wikipedia

    en.wikipedia.org/wiki/Spearman's_rank_correlation...

    Python has many different implementations of the spearman correlation statistic: it can be computed with the spearmanr function of the scipy.stats module, as well as with the DataFrame.corr(method='spearman') method from the pandas library, and the corr(x, y, method='spearman') function from the statistical package pingouin.

  8. Odds ratio - Wikipedia

    en.wikipedia.org/wiki/Odds_ratio

    An odds ratio (OR) is a statistic that quantifies the strength of the association between two events, A and B. The odds ratio is defined as the ratio of the odds of event A taking place in the presence of B, and the odds of A in the absence of B. Due to symmetry, odds ratio reciprocally calculates the ratio of the odds of B occurring in the presence of A, and the odds of B in the absence of A.

  9. Power (statistics) - Wikipedia

    en.wikipedia.org/wiki/Power_(statistics)

    At the same time, if defines its own probability distribution for t (the difference between the two distributions being a function of the effect size), the power of the test would be the probability, under , that the sample t falls into our defined rejection region and causes to be correctly rejected.