## 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.

## Statistical properties

A few commonly used statistical measures are calculated. Their definition is given below. n is the number of data points x. Note that these x- values do not need to be the numbers along some axis; they represent the values given in the selected cells in the data grid.

Standard Deviation (SD) – is a measure of the width of the distribution.
Skewness indicates the degree of asymmetry.
Kurtosis is a measure of the peakedness of the distribuition. For a Gaussian distribution it has the value 3. A more peaked ditribution has a Kurtosis larger than 3.

The Minimum and Maximum value and the Median are given as well as. By definition the number of values that are smaller than the Median equals the number that are larger.