SigmaXX Command

From GeoGebra Manual
Jump to: navigation, search




SigmaXX[ <List of Points> ]
Calculates the sum of squares of the x-coordinates of the given points.
Example: Let list = { (-3, 4), (-1, 4), (-2, 3), (1, 3), (2, 2), (1, 5) } be a list of points. SigmaXX[ Liste ] yields a = 20.


SigmaXX[ <List of Raw Data> ]
Calculates the sum of squares of the given numbers.
Example: In order to work out the variance of a list you may use SigmaXX[list] / Length[list] - Mean[list]^2.


SigmaXX[ <List of Numbers>, <List of Frequencies> ]
Calculates the weighted sum of squares of the given numbers.
Example: Let list = {3, 2, 4, 3, 3, 2, 1, 1, 2, 3, 3, 4, 5, 3, 2, 1, 1, 2, 3} be a list of numbers. Unique[ list1 ] yields list2 = {1, 2, 3, 4, 5} and Frequency[ list1 ] yields list3 = {4, 5, 7, 2, 1}. Command SigmaXX[ list2, list3 ] yields a = 144.
© 2024 International GeoGebra Institute