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Data
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# Data in 2D and 3D

Edit and select Data from a grid and draw a 2D or 3D Graph. You may view 3D data in the 3D viewer and make Contour plots and Cross-sections through Contour plots. Some statistical properties of the data may be calculated. You may also draw a histogram or the (cumulative, normalized) distribution function of selected data.
You may apply a Chi-square test or a Kolmogorov-Smirnov test to compare two distributions

Data: Statistics

# Chi-square test - 1 and 2

 Chi-square test - 1 and 2

 The Chi-square test is used to test differences between binned distributions. The selected Y-values in grid 1 and grid 2 are compared. In the first test the Y-values in grid 1 are assumed to represent a theoretical distribution. Chi-squared is defined as where Ni is the number in the i-th bin and ni is the number expectred according to some known distribution. Both distributions should contain the same total number of events.The probablity (0 where Ni and Mi are the numbers in the i-th bin of the distributions calculated in grid 1 and grid 2. The total numbers should be the same. The probablity P that the two distributions are drawn from the same underlying distribution is calculated. A small value of  P indicates that the two distributions are probably different.

 Kolmogorov-Smirnov test - 1 and 2

 The KS-test is used to test differences between unbinned distributions of a single continuous variable. The largest vertical difference D between the cumulative distributions is determined. This yields the probability that the two distributions are drawn from the same underlying distribution. The first test compares the data in grid 2 with a theoretical (normalized) distribution function defined in the Function panel. The second test compares (observed) data in grid 1 and grid 2.

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