空間資料的特性在於隨機變數之間並不獨立，而是會受到四周的觀測值影響，這種影響力又因兩兩之間的距離與方向不同而不同，一般而言，距離愈近，空間相關性愈高，但也有相反的可能。如果方向並不影響變數間的空間相關性，則空間隨機變數的共變異數只為距離的函數。規則格點形態之一階空間模型所考慮的方向只有東西向及南北向，本文針對該模型，探討兩方向相關係數是否相等的檢定，提出二個檢定統計量，並與概似比檢定量之檢定力作比較。

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