## 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.