calculate_star_statistics: Calculates the statistics for the crosssections of a Star

In JohMast/UrbanStars: Extract Statistics of Urban Centers

Description

Calculates the statistics for the crosssections of a Star

Usage

calculate_star_statistics(StarCrosssections, SubsetToUrban = F,
  UrbanLayerName, NDVILayerName, SlopeLayerName, AspectLayerName)

Arguments

StarCrosssections	a list of crosssections, as created by create_star_crosssections
SubsetToUrban	a switch indicating if the statistics should only be calculated for urban segments. Requires UrbanLayerName to be defined.
UrbanLayerName	name of the column which holds the urban density values
NDVILayerName	name of the column which holds the NDVI values
SlopeLayerName	name of the column which holds the slope values
AspectLayerName	name of the column which holds the aspect values

Details

The function calculates descriptive statistics for the distribution of the raster values extracted under a star.

If SubsetToUrban = T the statistics will be calculated only for the urban segments if the input StarCrosssections includes a logical column "IsUrban", as created by find_limit_star.

An UrbanLayerName is required and returns statistics for the building density distribution. Optionally, passing NDVILayerName, SlopeLayerName and AspectLayerName will return additional statistics. All Statistics are calculated for each of the crosssections individually and then averaged over all crosssections, weighted by their length. The exception is MeanUrbanCentralOffset, for which all crosssections are equally weighted.

Calculated statistics include:

1. MeanUrbanMean, the weighted mean of the means of the building density

2. MeanUrbanSkew, the weighted mean of the skews of the building density

3. MeanUrbanKurtosis, the weighted mean of the kurtosis of the building density

4. MeanUrbanVariance, the weighted mean of the variances of the building density

5. MeanUrbanCentralOff, the mean number of segments by which the maximum of the curves differ from the centers of the building density distributions.

6. MeanGreenMean, the weighted mean of the means of the NDVI distributions

7. MeanUrbanGreenness, the weighted mean of the scalar products of the building density and the NDVI distributions.

8. MeanUrbanGreennessCor, the weighted mean of the correlations of the building density and the NDVI distributions

9. MeanUrbanSlope, the weighted mean of the scalar products of the building density and the slope distributions.

10. MeanSlopeMean, the weighted mean of the means of the slope

11. MeanUrbanAspect, the weighted mean of the means of the aspect

Value

Dataframe

Author(s)

Johannes Mast

See Also

create_star_crosssections, find_limit

Examples

  calculate_star_statistics(
  StarCrosssections = StarCross,
  SubsetToUrban = F,
  UrbanLayerName = "GUFNorm",
  NDVILayerName = "NDVI",
  SlopeLayerName = "slope",
  AspectLayerName = "aspect")

JohMast/UrbanStars documentation built on May 28, 2019, 8:58 p.m.