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Surrogate data testing [1] (or the method of surrogate data) is a statistical proof by contradiction technique similar to permutation tests [2] and parametric bootstrapping. It is used to detect non-linearity in a time series . [ 3 ]
This metric is well suited to intermittent-demand series (a data set containing a large amount of zeros) because it never gives infinite or undefined values [1] except in the irrelevant case where all historical data are equal. [3] When comparing forecasting methods, the method with the lowest MASE is the preferred method.
In statistics, the Phillips–Perron test (named after Peter C. B. Phillips and Pierre Perron) is a unit root test. [1] That is, it is used in time series analysis to test the null hypothesis that a time series is integrated of order 1.
Vinod (2006), [31] presents a method that bootstraps time series data using maximum entropy principles satisfying the Ergodic theorem with mean-preserving and mass-preserving constraints. There is an R package, meboot , [ 32 ] that utilizes the method, which has applications in econometrics and computer science.
The nullity of a matrix is the dimension of the null space, and is equal to the number of columns in the reduced row echelon form that do not have pivots. [7] The rank and nullity of a matrix A with n columns are related by the equation:
Ideally, unevenly spaced time series are analyzed in their unaltered form. However, most of the basic theory for time series analysis was developed at a time when limitations in computing resources favored an analysis of equally spaced data, since in this case efficient linear algebra routines can be used and many problems have an explicit ...
Fisher's exact test, based on the work of Ronald Fisher and E. J. G. Pitman in the 1930s, is exact because the sampling distribution (conditional on the marginals) is known exactly. This should be compared with Pearson's chi-squared test , which (although it tests the same null) is not exact because the distribution of the test statistic is ...
The Chow test (Chinese: 鄒檢定), proposed by econometrician Gregory Chow in 1960, is a statistical test of whether the true coefficients in two linear regressions on different data sets are equal. In econometrics, it is most commonly used in time series analysis to test for the presence of a structural break at a period which can be assumed ...