TatukGIS is pleased to introduce a new general layer statistics class for computing statistics from data contained by any type of geospatial layer, e.g., vector, grid, image, and also custom datasets. Supported statistical functions include: average, count, count missings, maximum, majority, median, minimum, range, standard deviation, sum, variance, variety, and unique. Bessel's correction is available for sample variance and standard deviation.

Statistics can be computed for an entire layer or a portion of a layer determined by an extent, an attribute query, or a spatial query defined by a DE-9IM relationship (e.g., generate statistics for the area defined by a buffer).

Because calculating statistics for a huge image layer can be time consuming, a special option is implemented to generate fast approximated statistics for pixel layers.

Computing and accessing statistical data is easily performed via the Layer.Statistcs property. Read more about layer statistics in the DK documentation wiki at TGIS_StatisticsAbstract class, or explore the LayerStatistics sample. If using the TatukGIS Editor product, refer to the LayerStatistics script.

We currently work on further improvements such as providing statistical results as virtual attribute fields which can be used for map rendering, labeling, etc.

Fig.1. The LayerStatistics sample application overview.

Fig. 2. Statistical results for different layers.
Posted: March 26, 2019
Filed under: DK, EDT, SCRIPTING