hcapi3 3.7

Rank spatial units by similarity

Usage

similar(x, var, by = 0, iso3 = "SSA")

Arguments

x
single integer code for the reference geography, either a region code (ADM1_CODE_ALT), district code (ADM2_CODE_ALT), or gridcell code (CELL5M) to rank against
var
character array of HarvestChoice variable codes used in the ranking
by
single integer indicating the type of reference geography (0-gridcell, 1-region, 2-district)
iso3
optional country or region filter (3-letter code)

Value

a data.table of regions, districts, or pixels ranked by similarity to a reference geography x

Description

Rank regions, districts, or pixels by similarity to a reference unit across a set of indicators. To generate a distance score, we center and scale all numeric variables and convert classified variables to 0 or 1 (1 if same as reference unit, 0 otherwise). For each variable we compute the absolute percent deviation between each unit and the reference unit, and we then sum the deviations across all variables to generate an aggregate distance score. The lower the score, the more similar the unit for the selected indicators.

Details

API call: rank Ghana districts by similarity to district 16657 (Kpando) based on length of growing period, irrigated area, and cassava value of production

$ curl http://hcapi.harvestchoice.org/ocpu/library/hcapi3/R/similar/json \ -d '{"x" : 16657, "var" : ["LGP_AVG", "GMIA_V5", "cass_v"], "by" : 2, "iso3" : "GHA"}' \ -X POST -H "Content-Type:application/json"

Examples

# Rank all districts in Ghana by similarity to district 16657 (Kpando)
# based on length of growing period (LGP_AVG), irrigated cropland (GMIA_V5),
# and cassava value of production (cass_v).
similar(16657, c("LGP_AVG", "GMIA_V5", "cass_v"), by=2, iso3="GHA")



     ISO3 ADM0_NAME ADM2_CODE_ALT LGP_AVG GMIA_V5   cass_v     Score
  1:  GHA     Ghana         16657     278       0  3021856 0.0000000
  2:  GHA     Ghana         16575     287       0  3172796 0.2157802
  3:  GHA     Ghana         16595     265      28  3176379 0.3335517
  4:  GHA     Ghana         16651     273       0  5486071 0.3914655
  5:  GHA     Ghana         16652     271      97  5449375 0.5322633
 ---                                                                
106:  GHA     Ghana         16636     181    3008  3471751 5.3190665
107:  GHA     Ghana         16658     230       0 41057948 5.3987159
108:  GHA     Ghana         16644     169    3096        0 5.9687622
109:  GHA     Ghana         16618     283    4633 17700273 6.6024348
110:  GHA     Ghana         16628     178     153 45721318 7.2371012