UN_plot_boxplot: Boxplot of a vector
In polgia0/Chemometricmenus: Chemometric package

Description Usage Arguments Details Value Author(s) Examples

Boxplot of a vector

1	UN_plot_boxplot(previous.name = "")

previous.name

name of the default name in the menu

Vectorname of the vector dataset

The data distribution plays an important role in statistics; chemometrics is not so happy with this concept because the number of available data is often small and the type of distribution is often unknown. Actually, the value of a variable x (say the concentration of a chemical compound in a set of n samples) will have an Empirical Distribution; whenever possible the distribution of x should be visually inspected to obtain a better insight of the data. A number of different plots can be used for this purpose. The boldBoxplot function is an informative graphics to display a data distribution, based on median and quartiles. According to Frank and Todeschini (1994) a boxplot can be defined as follows ): The height of the box is given by the first and third quartile, and the mid line shows the median; the width of the box has usually no meaning. One whisker extends from the first quartile to the smallest data value in the interval Q1 to Q1-1.5IQR and is called the lower whisker. The other whisker extends from the third quartile to the largest data value in the interval Q3 to Q3+1.5IQR and is called the upper whisker. Outliers,not within the range Q1-1.5IQR, Q3+1.5IQR, are plotted as individual points.

A window plot

Riccardo Leardi and Gianmarco Polotti with contributions from Giorgio Marubini.Gruppo di Chemiometria (Divisione di Chimica Analitica della Societa' Chimica Italiana)