Gegevens toevoegen aan ruimtelijke objecten

Georuimtelijke data visualiseren in R

Charlotte Wickham

Assistant Professor at Oregon State University

Inkomensdata uit ACS

str(nyc_income)

'data.frame':    288 obs. of  6 variables:
 $ name    : chr  "Census Tract 1, New York County, New York" 
 "Census Tract 2.01, New York County, New York" 
 "Census Tract 2.02, New York County, New York" 
 "Census Tract 5, New York County, New York" ...
 $ state   : int  36 36 36 36 36 36 36 36 36 36 ...
 $ county  : int  61 61 61 61 61 61 61 61 61 61 ...
 $ tract   : chr  "000100" "000201" "000202" "000500" ...
 $ estimate: num  NA 23036 29418 NA 18944 ...
 $ se      : num  NA 3083 1877 NA 1442 ...

Tract-polygondata

str(nyc_tracts, max.level = 2)

Formal class 'SpatialPolygonsDataFrame' [package "sp"] with 5 slots
  ..@ data       :'data.frame':    288 obs. of  9 variables:
  ..@ polygons   :List of 288
  .. .. [list output truncated]
  ..@ plotOrder  : int [1:288] 175 225 97 209 249 232 208 247 244 207 ...
  ..@ bbox       : num [1:2, 1:2] -74 40.7 -73.9 40.9
  .. ..- attr(*, "dimnames")=List of 2
  ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slot

Tract-polygondata

str(nyc_tracts@data)

'data.frame':    288 obs. of  9 variables:
 $ STATEFP : chr  "36" "36" "36" "36" ...
 $ COUNTYFP: chr  "061" "061" "061" "061" ...
 $ TRACTCE : chr  "001401" "002201" "003200" "004000" ...
 $ AFFGEOID: chr  "1400000US36061001401" "1400000US36061002201" 
 "1400000US36061003200" "1400000US36061004000" ...
 $ GEOID   : chr  "36061001401" "36061002201" "36061003200" "36061004000" ...
 $ NAME    : chr  "14.01" "22.01" "32" "40" ...
 $ LSAD    : chr  "CT" "CT" "CT" "CT" ...
 $ ALAND   : num  93510 161667 217682 178340 124447 ...
 $ AWATER  : num  0 0 0 0 0 0 0 0 0 0 ...

Doel: voeg de geschatte mediane inkomen toe aan dit data frame

Overeenkomst tussen polygonen en data

four_tracts

class       : SpatialPolygons 
features    : 4 
extent      : -73.99022, (xmin)
              -73.97875, (xmax)
              40.71413,  (ymin)
              40.73329   (ymax)
coord. ref. : +proj=longlat +datum=NAD83
              +no_defs +ellps=GRS80 
              +towgs84=0,0,0

sapply(four_tracts@polygons,
       function(x) x@ID)

"156" "157" "158" "159"

four_data

    TRACTCE
159  004000
158  003200
157  002201
156  001401

Overeenkomst tussen polygonen en data

SpatialPolygonsDataFrame(Sr, data, match.ID = TRUE)

SpatialPolygonsDataFrame(four_tracts, four_data)

class       : SpatialPolygonsDataFrame 
features    : 4 
extent      : -73.99022, -73.97875, 40.71413, 40.73329  (xmin, xmax, ymin, ymax)
coord. ref. : +proj=longlat +datum=NAD83 +no_defs +ellps=GRS80 +towgs84=0,0,0 
variables   : 1
names       : TRACTCE 
min values  :  001401 
max values  :  004000

Overeenkomst tussen polygonen en data

SpatialPolygonsDataFrame(Sr, data, match.ID = TRUE)

SpatialPolygonsDataFrame(four_tracts, four_data)@data

    TRACTCE
156  001401
157  002201
158  003200
159  004000

Overeenkomst tussen polygonen en data

SpatialPolygonsDataFrame(four_tracts, four_data, match.ID = FALSE)@data

    TRACTCE
159  004000
158  003200
157  002201
156  001401

Overeenkomst is nu weg!

Nieuwe data toevoegen

Na creatie zijn er geen checks dat data bij de juiste polygonen blijven
Maak het object opnieuw en koppel polygonen zorgvuldig aan de juiste rijen
sp::merge(), merge() voor sp-objecten

Laten we oefenen!

Georuimtelijke data visualiseren in R