aw_calculate multiplies the given value by the area weight. This
is the fourth step in the interpolation process after aw_weight.
aw_calculate(.data, value, areaWeight, newVar)A given intersected dataset
A column within source to be interpolated
The name of the variable containing area weight per feature
Optional; a new field name to store the interpolated value in. If not specified,
the value argument will be used as the new field name.
An intersected file of class sf with a new field of interest recalculated with area weight
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") %>%
aw_weight(areaVar = "area", totalVar = "totalArea", areaWeight = "areaWeight") -> intersect
aw_calculate(intersect, value = "TOTAL_E", 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 1.148421e+03 1 4.268099e+05 1064032.5
#> 2 29510106700 1.520247e+03 1 5.942485e+05 1238338.0
#> 3 29510107500 1.341296e+03 1 6.141786e+05 911677.5
#> 4 29510107600 1.800575e+03 1 1.074142e+06 1168054.2
#> 5 29510110100 1.577594e-01 1 5.559584e+01 993793.8
#> 6 29510126900 9.164090e+02 1 8.896824e+05 4331867.8
#> 7 29510127000 1.260681e-01 1 1.014709e+03 14697280.1
#> 8 29510108100 1.239119e-01 1 1.197780e+02 3198604.2
#> 9 29510106400 1.231736e+03 1 6.861954e+05 1106392.9
#> 10 29510107500 3.382533e-02 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