Fig. 6From: Comparison of estimators of variance for forest inventories with systematic sampling - results from artificial populationsAn example of ordering a systematic sample from a spatial population arranged in a regular array. A row-wise ordering (top left), a column-wise ordering (top right), and the shortest path through a sample of n = 400 units selected with a sampling interval of 12 from a population with a regular array of 240 × 240 units (bottom). The two dots indicate the start and finish of the pathBack to article page