|
Geary's ''C'' is a measure of spatial autocorrelation or an attempt to determine if adjacent observations of the same phenomenon are correlated. Spatial autocorrelation is more complex than autocorrelation because the correlation is multi-dimensional and bi-directional. Geary's ''C'' is defined as : where is the number of spatial units indexed by and ; is the variable of interest; is the mean of ; is a matrix of spatial weights; and is the sum of all . The value of Geary's ''C'' lies between 0 and 2. 1 means no spatial autocorrelation. Values lower than 1 demonstrate increasing positive spatial autocorrelation, whilst values higher than 1 illustrate increasing negative spatial autocorrelation. Geary's ''C'' is inversely related to Moran's ''I'', but it is not identical. Moran's ''I'' is a measure of global spatial autocorrelation, while Geary's ''C'' is more sensitive to local spatial autocorrelation. Geary's ''C'' is also known as Geary's contiguity ratio or simply Geary's ratio. This statistic was developed by Roy C. Geary. ==Sources== 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Geary's C」の詳細全文を読む スポンサード リンク
|