aw_weight creates an area weight field by dividing the area
field by the total area field. This is the third step in the interpolation
process after aw_weight.
aw_weight(.data, areaVar, totalVar, areaWeight)A sf object that has been intersected using aw_intersect
The name of the variable measuring a feature's area
The name of the variable containing total area field by source id
The name of a new area weight field to be calculated
A sf object with the intersected data and new area weight field.
library(dplyr)
race <- select(ar_stl_race, GEOID, TOTAL_E)
wards <- select(ar_stl_wards, WARD)
wards %>%
aw_intersect(source = race, areaVar = "area") %>%
aw_total(source = race, id = GEOID, areaVar = "area", totalVar = "totalArea",
weight = "sum", type = "extensive") -> intersect
aw_weight(intersect, areaVar = "area", totalVar = "totalArea", areaWeight = "areaWeight")
#> Simple feature collection with 286 features and 6 fields
#> Geometry type: GEOMETRY
#> Dimension: XY
#> Bounding box: xmin: 265638 ymin: 299509.9 xmax: 278973 ymax: 326430.3
#> Projected CRS: NAD_1983_HARN_StatePlane_Missouri_East_FIPS_2401
#> First 10 features:
#> GEOID TOTAL_E WARD area totalArea
#> 1 29510106500 2863 1 4.268099e+05 1064032.5
#> 2 29510106700 3168 1 5.942485e+05 1238338.0
#> 3 29510107500 1991 1 6.141786e+05 911677.5
#> 4 29510107600 1958 1 1.074142e+06 1168054.2
#> 5 29510110100 2820 1 5.559584e+01 993793.8
#> 6 29510126900 4462 1 8.896824e+05 4331867.8
#> 7 29510127000 1826 1 1.014709e+03 14697280.1
#> 8 29510108100 3309 1 1.197780e+02 3198604.2
#> 9 29510106400 1986 1 6.861954e+05 1106392.9
#> 10 29510107500 1991 2 1.548859e+01 911677.5
#> geometry areaWeight
#> 1 POLYGON ((270624.5 315101.4... 4.011249e-01
#> 2 POLYGON ((270823.1 314161.8... 4.798758e-01
#> 3 POLYGON ((272693.4 317603.1... 6.736797e-01
#> 4 POLYGON ((271928.5 316159, ... 9.195993e-01
#> 5 POLYGON ((272047.9 314802.1... 5.594303e-05
#> 6 POLYGON ((271678.3 316891, ... 2.053808e-01
#> 7 MULTIPOLYGON (((273486.1 31... 6.904061e-05
#> 8 POLYGON ((272743.5 317521.7... 3.744694e-05
#> 9 POLYGON ((271034.9 315851.6... 6.202095e-01
#> 10 POLYGON ((272862.1 317334.3... 1.698911e-05