XploRe Help : twpearson

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Library:	tware
See also:	twrandomsample twpvalue twnormalize tw1d twlinreg twclt

Quantlet:		twpearson
Description:		the teachware quantlet twpearson gives a visual demonstration of the form of the Pearson correlation coefficient. In particular, it shows why the product moment gives a measure of "dependence", and why it is essential to "normalize", i.e. to subtract means, and divide by standard deviations, to preserve that property.

Reference(s):

Hardle, W., Klinke, S. and Marron, J.S. (1999) Connected teaching of statistics

Usage:	`twpearson({x})`
Input:
	`x`	matrix (n x 2) with user defined data

Note:

The parameter x is optional. If it is not given, the user is asked to define the desired correlation interactively.

Example:

; load teachware library library("tware") ; predefine matrix x = normal(100,2) ; call twpearson teachware quantlet twpearson(x)

Result:

a two window port display with the scatterplot of the matrix x
in the upper port and the values of the product moments
in the lower (text) port.

Author: S. Klinke, W. Haerdle, 20010912 license MD*Tech