Make a choropleth map

 //.. 
 let 
  
 featureLayer 
  
 = 
  
 mapView 
 . 
 featureLayer 
 ( 
 of 
 : 
  
 FeatureType 
 . 
 administrativeAreaLevel1 
 ) 
 let 
  
 populationOfStates 
  
 = 
  
 [ 
 "ChIJdf5LHzR_hogR6czIUzU0VV4" 
 : 
  
 5_039_877 
 , 
 "ChIJG8CuwJzfAFQRNduKqSde27w" 
 : 
  
 732673 
 , 
 "ChIJaxhMy-sIK4cRcc3Bf7EnOUI" 
 : 
  
 7_276_316 
 , 
 "ChIJYSc_dD-e0ocR0NLf_z5pBaQ" 
 : 
  
 3_025_891 
 , 
 "ChIJPV4oX_65j4ARVW8IJ6IJUYs" 
 : 
  
 39_237_836 
 , 
  
 // California 
 "ChIJt1YYm3QUQIcR_6eQSTGDVMc" 
 : 
  
 5_812_069 
 , 
 "ChIJpVER8hFT5okR5XBhBVttmq4" 
 : 
  
 3_605_597 
 , 
 "ChIJO9YMTXYFx4kReOgEjBItHZQ" 
 : 
  
 1_003_384 
 , 
 "ChIJvypWkWV2wYgR0E7HW9MTLvc" 
 : 
  
 21_781_128 
 , 
 "ChIJV4FfHcU28YgR5xBP7BC8hGY" 
 : 
  
 10_799_566 
 , 
 "ChIJBeB5Twbb_3sRKIbMdNKCd0s" 
 : 
  
 1_441_553 
 , 
 "ChIJ6Znkhaj_WFMRWIf3FQUwa9A" 
 : 
  
 1_900_923 
 , 
 "ChIJGSZubzgtC4gRVlkRZFCCFX8" 
 : 
  
 12_671_469 
 , 
 "ChIJHRv42bxQa4gRcuwyy84vEH4" 
 : 
  
 6_805_985 
 , 
 "ChIJGWD48W9e7ocR2VnHV0pj78Y" 
 : 
  
 3_193_079 
 , 
 "ChIJawF8cXEXo4cRXwk-S6m0wmg" 
 : 
  
 2_934_582 
 , 
 "ChIJyVMZi0xzQogR_N_MxU5vH3c" 
 : 
  
 4_509_394 
 , 
 "ChIJZYIRslSkIIYRA0flgTL3Vck" 
 : 
  
 4_624_047 
 , 
 "ChIJ1YpTHd4dsEwR0KggZ2_MedY" 
 : 
  
 1_372_247 
 , 
 "ChIJ35Dx6etNtokRsfZVdmU3r_I" 
 : 
  
 6_165_129 
 , 
 "ChIJ_b9z6W1l44kRHA2DVTbQxkU" 
 : 
  
 6_984_723 
 , 
 "ChIJEQTKxz2qTE0Rs8liellI3Zc" 
 : 
  
 10_050_811 
 , 
 "ChIJmwt4YJpbWE0RD6L-EJvJogI" 
 : 
  
 5_707_390 
 , 
 "ChIJGdRK5OQyKIYR2qbc6X8XDWI" 
 : 
  
 2_949_965 
 , 
 "ChIJfeMiSNXmwIcRcr1mBFnEW7U" 
 : 
  
 6_168_187 
 , 
 "ChIJ04p7LZwrQVMRGGwqz1jWcfU" 
 : 
  
 1_104_271 
 , 
 "ChIJ7fwMtciNk4cRxArzDwyQJ6E" 
 : 
  
 1_963_692 
 , 
 "ChIJcbTe-KEKmYARs5X8qooDR88" 
 : 
  
 3_143_991 
 , 
 "ChIJ66bAnUtEs0wR64CmJa8CyNc" 
 : 
  
 1_388_992 
 , 
 "ChIJn0AAnpX7wIkRjW0_-Ad70iw" 
 : 
  
 9_267_130 
 , 
 "ChIJqVKY50NQGIcRup41Yxpuv0Y" 
 : 
  
 2_115_877 
 , 
 "ChIJqaUj8fBLzEwRZ5UY3sHGz90" 
 : 
  
 19_835_913 
 , 
 "ChIJgRo4_MQfVIgRGa4i6fUwP60" 
 : 
  
 10_551_162 
 , 
 "ChIJY-nYVxKD11IRyc9egzmahA0" 
 : 
  
 774948 
 , 
 "ChIJwY5NtXrpNogRFtmfnDlkzeU" 
 : 
  
 11_780_017 
 , 
 "ChIJnU-ssRE5rIcRSOoKQDPPHF0" 
 : 
  
 3_986_639 
 , 
 "ChIJVWqfm3xuk1QRdrgLettlTH0" 
 : 
  
 4_246_155 
 , 
 "ChIJieUyHiaALYgRPbQiUEchRsI" 
 : 
  
 12_964_056 
 , 
 "ChIJD9cOYhQ15IkR5wbB57wYTh4" 
 : 
  
 1_095_610 
 , 
 "ChIJ49ExeWml-IgRnhcF9TKh_7k" 
 : 
  
 5_190_705 
 , 
 "ChIJpTjphS1DfYcRt6SGMSnW8Ac" 
 : 
  
 895376 
 , 
 "ChIJA8-XniNLYYgRVpGBpcEgPgM" 
 : 
  
 6_975_218 
 , 
 "ChIJSTKCCzZwQIYRPN4IGI8c6xY" 
 : 
  
 29_527_941 
 , 
 "ChIJzfkTj8drTIcRP0bXbKVK370" 
 : 
  
 3_337_975 
 , 
 "ChIJ_87aSGzctEwRtGtUNnSJTSY" 
 : 
  
 645570 
 , 
 "ChIJzbK8vXDWTIgRlaZGt0lBTsA" 
 : 
  
 8_642_274 
 , 
 "ChIJ-bDD5__lhVQRuvNfbGh4QpQ" 
 : 
  
 7_738_692 
 , 
 "ChIJRQnL1KVUSogRQzrN3mjHALs" 
 : 
  
 1_782_959 
 , 
 "ChIJr-OEkw_0qFIR1kmG-LjV1fI" 
 : 
  
 5_895_908 
 , 
 "ChIJaS7hSDTiXocRLzh90nkisCY" 
 : 
  
 578803 
 , 
  
 // Wyoming 
 ] 
 featureLayer 
 . 
 style 
  
 = 
  
 { 
  
 feature 
  
 in 
  
 FeatureStyle 
 ( 
  
 fill 
 : 
  
 populationOfStates 
 [ 
 feature 
 . 
 placeID 
 ]. 
 map 
  
 { 
  
 UIColor 
 ( 
  
 hue 
 : 
  
 log 
 ( 
 CGFloat 
 ( 
 $0 
 ) 
  
 / 
  
 5e5 
 ) 
  
 / 
  
 7.5 
 , 
  
 saturation 
 : 
  
 1 
 , 
  
 brightness 
 : 
  
 0.75 
 , 
  
 alpha 
 : 
  
 0.5 
 ) 
  
 } 
  
 ?? 
  
 nil 
 , 
  
 stroke 
 : 
  
 nil 
 , 
  
 strokeWidth 
 : 
  
 0 
  
 ) 
 } 
 self 
 . 
 view 
  
 = 
  
 mapView 

 //.. 
 GMSFeatureLayer<GMSPlaceFeature 
 *> 
* featureLayer 
  
 = 
  
 [ 
 mapView 
  
 featureLayerOfFeatureType 
 : 
 GMSFeatureTypeAdministrativeAreaLevel1 
 ]; 
 NSDictionary<NSString 
  
* , 
  
 NSNumber 
 *> 
 * 
 populationOfStates 
  
 = 
  
 @{ 
  
 @"ChIJdf5LHzR_hogR6czIUzU0VV4" 
  
 : 
  
 @( 
 5039877 
 ) 
 , 
  
 @"ChIJG8CuwJzfAFQRNduKqSde27w" 
  
 : 
  
 @( 
 732673 
 ) 
 , 
  
 @"ChIJaxhMy-sIK4cRcc3Bf7EnOUI" 
  
 : 
  
 @( 
 7276316 
 ) 
 , 
  
 @"ChIJYSc_dD-e0ocR0NLf_z5pBaQ" 
  
 : 
  
 @( 
 3025891 
 ) 
 , 
  
 @"ChIJPV4oX_65j4ARVW8IJ6IJUYs" 
  
 : 
  
 @( 
 39237836 
 ) 
 , 
  
 // California 
  
 @"ChIJt1YYm3QUQIcR_6eQSTGDVMc" 
  
 : 
  
 @( 
 5812069 
 ) 
 , 
  
 @"ChIJpVER8hFT5okR5XBhBVttmq4" 
  
 : 
  
 @( 
 3605597 
 ) 
 , 
  
 @"ChIJO9YMTXYFx4kReOgEjBItHZQ" 
  
 : 
  
 @( 
 1003384 
 ) 
 , 
  
 @"ChIJvypWkWV2wYgR0E7HW9MTLvc" 
  
 : 
  
 @( 
 21781128 
 ) 
 , 
  
 @"ChIJV4FfHcU28YgR5xBP7BC8hGY" 
  
 : 
  
 @( 
 10799566 
 ) 
 , 
  
 @"ChIJBeB5Twbb_3sRKIbMdNKCd0s" 
  
 : 
  
 @( 
 1441553 
 ) 
 , 
  
 @"ChIJ6Znkhaj_WFMRWIf3FQUwa9A" 
  
 : 
  
 @( 
 1900923 
 ) 
 , 
  
 @"ChIJGSZubzgtC4gRVlkRZFCCFX8" 
  
 : 
  
 @( 
 12671469 
 ) 
 , 
  
 @"ChIJHRv42bxQa4gRcuwyy84vEH4" 
  
 : 
  
 @( 
 6805985 
 ) 
 , 
  
 @"ChIJGWD48W9e7ocR2VnHV0pj78Y" 
  
 : 
  
 @( 
 3193079 
 ) 
 , 
  
 @"ChIJawF8cXEXo4cRXwk-S6m0wmg" 
  
 : 
  
 @( 
 2934582 
 ) 
 , 
  
 @"ChIJyVMZi0xzQogR_N_MxU5vH3c" 
  
 : 
  
 @( 
 4509394 
 ) 
 , 
  
 @"ChIJZYIRslSkIIYRA0flgTL3Vck" 
  
 : 
  
 @( 
 4624047 
 ) 
 , 
  
 @"ChIJ1YpTHd4dsEwR0KggZ2_MedY" 
  
 : 
  
 @( 
 1372247 
 ) 
 , 
  
 @"ChIJ35Dx6etNtokRsfZVdmU3r_I" 
  
 : 
  
 @( 
 6165129 
 ) 
 , 
  
 @"ChIJ_b9z6W1l44kRHA2DVTbQxkU" 
  
 : 
  
 @( 
 6984723 
 ) 
 , 
  
 @"ChIJEQTKxz2qTE0Rs8liellI3Zc" 
  
 : 
  
 @( 
 10050811 
 ) 
 , 
  
 @"ChIJmwt4YJpbWE0RD6L-EJvJogI" 
  
 : 
  
 @( 
 5707390 
 ) 
 , 
  
 @"ChIJGdRK5OQyKIYR2qbc6X8XDWI" 
  
 : 
  
 @( 
 2949965 
 ) 
 , 
  
 @"ChIJfeMiSNXmwIcRcr1mBFnEW7U" 
  
 : 
  
 @( 
 6168187 
 ) 
 , 
  
 @"ChIJ04p7LZwrQVMRGGwqz1jWcfU" 
  
 : 
  
 @( 
 1104271 
 ) 
 , 
  
 @"ChIJ7fwMtciNk4cRxArzDwyQJ6E" 
  
 : 
  
 @( 
 1963692 
 ) 
 , 
  
 @"ChIJcbTe-KEKmYARs5X8qooDR88" 
  
 : 
  
 @( 
 3143991 
 ) 
 , 
  
 @"ChIJ66bAnUtEs0wR64CmJa8CyNc" 
  
 : 
  
 @( 
 1388992 
 ) 
 , 
  
 @"ChIJn0AAnpX7wIkRjW0_-Ad70iw" 
  
 : 
  
 @( 
 9267130 
 ) 
 , 
  
 @"ChIJqVKY50NQGIcRup41Yxpuv0Y" 
  
 : 
  
 @( 
 2115877 
 ) 
 , 
  
 @"ChIJqaUj8fBLzEwRZ5UY3sHGz90" 
  
 : 
  
 @( 
 19835913 
 ) 
 , 
  
 @"ChIJgRo4_MQfVIgRGa4i6fUwP60" 
  
 : 
  
 @( 
 10551162 
 ) 
 , 
  
 @"ChIJY-nYVxKD11IRyc9egzmahA0" 
  
 : 
  
 @( 
 774948 
 ) 
 , 
  
 @"ChIJwY5NtXrpNogRFtmfnDlkzeU" 
  
 : 
  
 @( 
 11780017 
 ) 
 , 
  
 @"ChIJnU-ssRE5rIcRSOoKQDPPHF0" 
  
 : 
  
 @( 
 3986639 
 ) 
 , 
  
 @"ChIJVWqfm3xuk1QRdrgLettlTH0" 
  
 : 
  
 @( 
 4246155 
 ) 
 , 
  
 @"ChIJieUyHiaALYgRPbQiUEchRsI" 
  
 : 
  
 @( 
 12964056 
 ) 
 , 
  
 @"ChIJD9cOYhQ15IkR5wbB57wYTh4" 
  
 : 
  
 @( 
 1095610 
 ) 
 , 
  
 @"ChIJ49ExeWml-IgRnhcF9TKh_7k" 
  
 : 
  
 @( 
 5190705 
 ) 
 , 
  
 @"ChIJpTjphS1DfYcRt6SGMSnW8Ac" 
  
 : 
  
 @( 
 895376 
 ) 
 , 
  
 @"ChIJA8-XniNLYYgRVpGBpcEgPgM" 
  
 : 
  
 @( 
 6975218 
 ) 
 , 
  
 @"ChIJSTKCCzZwQIYRPN4IGI8c6xY" 
  
 : 
  
 @( 
 29527941 
 ) 
 , 
  
 @"ChIJzfkTj8drTIcRP0bXbKVK370" 
  
 : 
  
 @( 
 3337975 
 ) 
 , 
  
 @"ChIJ_87aSGzctEwRtGtUNnSJTSY" 
  
 : 
  
 @( 
 645570 
 ) 
 , 
  
 @"ChIJzbK8vXDWTIgRlaZGt0lBTsA" 
  
 : 
  
 @( 
 8642274 
 ) 
 , 
  
 @"ChIJ-bDD5__lhVQRuvNfbGh4QpQ" 
  
 : 
  
 @( 
 7738692 
 ) 
 , 
  
 @"ChIJRQnL1KVUSogRQzrN3mjHALs" 
  
 : 
  
 @( 
 1782959 
 ) 
 , 
  
 @"ChIJr-OEkw_0qFIR1kmG-LjV1fI" 
  
 : 
  
 @( 
 5895908 
 ) 
 , 
  
 @"ChIJaS7hSDTiXocRLzh90nkisCY" 
  
 : 
  
 @( 
 578803 
 ) 
 , 
  
 // Wyoming 
 } 
 ; 
 featureLayer 
 . 
 style 
  
 = 
  
 ^ 
 ( 
 GMSPlaceFeature 
  
 * 
 feature 
 ) 
  
 { 
  
 NSNumber 
  
 * 
 population 
  
 = 
  
 populationOfStates 
 [ 
 feature 
 . 
 placeID 
 ]; 
  
 UIColor 
  
 * 
 fillColor 
  
 = 
  
 population 
  
 ? 
  
 [ 
 UIColor 
  
 colorWithHue 
 : 
 ( 
 log 
 ( 
 population 
 . 
 doubleValue 
  
 / 
  
 5e5 
 ) 
  
 / 
  
 7.5 
 ) 
  
 saturation 
 : 
 1 
  
 brightness 
 : 
 0.5 
  
 alpha 
 : 
 0.5 
 ] 
  
 : 
  
 nil 
 ; 
  
 return 
  
 [ 
 GMSFeatureStyle 
  
 styleWithFillColor 
 : 
 fillColor 
  
 strokeColor 
 : 
 nil 
  
 strokeWidth 
 : 
 0.0 
 ]; 
 }; 
 self 
 . 
 view 
  
 = 
  
 mapView 
 ;