Friday, 22 November 2013

Q-Q plotter for Gaussian Distribution

Enter first dataset samples

This blog post implements a Q-Q (Quantile-Quantile) plot of a single dataset against the Gaussian distribution. The more Gaussian the data is, the more linear will the Q-Q plot be. The horizontal axis of the plot is the Quantile of the Gaussian distribution with the same mean and variance as the data under test.

The above text box stores the single dataset and needs to be filled in with comma separated numbers. Alternatively, you can choose the file entry method, whereby you select a single column CSV file by pressing the Choose File button.

The graphs at the bottom will display the Q-Q plot for the datasets, once the Plot Q-Q button is pressed.

You can initiate the zoom facility by first pressing the Plot Gaussian Q-Q Plot button, then selecting a rectangle in either the shorter ("overview") graph display or in the main graph. To undo the zoom process, simply press the Plot button again.

Below the graphs, summary statistics for the dataset under test will be displayed when the Plot Q-Q button is pressed.

Q-Q plot
Sample value

Statistical results..