My Census developer API Key
census_api_key(key = "8c0b6ab768e3e309934cd84592d09c2ee27ce193", install = T,overwrite=TRUE )
## Your original .Renviron will be backed up and stored in your R HOME directory if needed.
## Your API key has been stored in your .Renviron and can be accessed by Sys.getenv("CENSUS_API_KEY").
## To use now, restart R or run `readRenviron("~/.Renviron")`
## [1] "8c0b6ab768e3e309934cd84592d09c2ee27ce193"
v11_Profile <- load_variables(2011, "acs5/profile", cache = TRUE) #demographic profile tables
v19_Profile <- load_variables(2019, "acs5/profile", cache = TRUE) #demographic
#Search for variables by using grep()
v11_Profile[grep(x = v11_Profile$label, "PERCENT VACANT HOUSING UNITS", ignore.case = TRUE), c("name", "label")]
## # A tibble: 0 x 2
## # ... with 2 variables: name <chr>, label <chr>
v19_Profile[grep(x = v19_Profile$label, "PERCENT VACANT HOUSING UNITS", ignore.case = TRUE), c("name", "label")]
## # A tibble: 0 x 2
## # ... with 2 variables: name <chr>, label <chr>
Extract from ACS summary file data profile variables from 2011 and 2019 for Galveston County, TX Census Tracts
VHU11<-get_acs(geography = "tract",
state="TX",
county = "Galveston",
year = 2011,
variables="DP04_0003P",
geometry = T,
output = "wide")
## Getting data from the 2007-2011 5-year ACS
## Downloading feature geometry from the Census website. To cache shapefiles for use in future sessions, set `options(tigris_use_cache = TRUE)`.
## Using the ACS Data Profile
VHU19<-get_acs(geography = "tract",
state="TX",
county = "Galveston",
year = 2019,
variables="DP04_0003P",
geometry = T,
output = "wide")
## Getting data from the 2015-2019 5-year ACS
## Downloading feature geometry from the Census website. To cache shapefiles for use in future sessions, set `options(tigris_use_cache = TRUE)`.
## Using the ACS Data Profile
#rename variables and filter missing cases
VHU11 <- VHU11%>%
mutate(VHU11 = DP04_0003PE,
VHU11_er = DP04_0003PM/1.645,
VHU11_cv =100* (VHU11_er/VHU11)) %>%
filter(complete.cases(VHU11), is.finite(VHU11_cv)==T)
head(VHU11)
## Simple feature collection with 6 features and 7 fields
## geometry type: POLYGON
## dimension: XY
## bbox: xmin: -95.23308 ymin: 29.29611 xmax: -94.92506 ymax: 29.52631
## geographic CRS: NAD83
## GEOID NAME DP04_0003PE
## 1 48167720302 Census Tract 7203.02, Galveston County, Texas 0.8
## 2 48167720502 Census Tract 7205.02, Galveston County, Texas 6.0
## 3 48167720501 Census Tract 7205.01, Galveston County, Texas 3.7
## 4 48167721202 Census Tract 7212.02, Galveston County, Texas 2.5
## 5 48167722002 Census Tract 7220.02, Galveston County, Texas 6.7
## 6 48167723502 Census Tract 7235.02, Galveston County, Texas 3.9
## DP04_0003PM geometry VHU11 VHU11_er VHU11_cv
## 1 1.4 POLYGON ((-95.23098 29.4754... 0.8 0.8510638 106.38298
## 2 4.6 POLYGON ((-95.12573 29.4685... 6.0 2.7963526 46.60588
## 3 4.1 POLYGON ((-95.13526 29.4973... 3.7 2.4924012 67.36220
## 4 4.2 POLYGON ((-95.06361 29.4849... 2.5 2.5531915 102.12766
## 5 5.0 POLYGON ((-94.93173 29.3952... 6.7 3.0395137 45.36588
## 6 3.0 POLYGON ((-95.08098 29.3434... 3.9 1.8237082 46.76175
VHU19 <- VHU19%>%
mutate(VHU19 = DP04_0003PE,
VHU19_er = DP04_0003PM/1.645,
VHU19_cv =100* (VHU19_er/VHU19)) %>%
filter(complete.cases(VHU19), is.finite(VHU19_cv)==T)
head(VHU19)
## Simple feature collection with 6 features and 7 fields
## geometry type: MULTIPOLYGON
## dimension: XY
## bbox: xmin: -95.09076 ymin: 29.2863 xmax: -94.8109 ymax: 29.48285
## geographic CRS: NAD83
## GEOID NAME DP04_0003PE
## 1 48167720800 Census Tract 7208, Galveston County, Texas 15.2
## 2 48167720900 Census Tract 7209, Galveston County, Texas 23.1
## 3 48167725200 Census Tract 7252, Galveston County, Texas 11.0
## 4 48167722200 Census Tract 7222, Galveston County, Texas 14.7
## 5 48167722700 Census Tract 7227, Galveston County, Texas 16.7
## 6 48167722800 Census Tract 7228, Galveston County, Texas 16.8
## DP04_0003PM geometry VHU19 VHU19_er VHU19_cv
## 1 7.3 MULTIPOLYGON (((-95.09076 2... 15.2 4.437690 29.19533
## 2 5.8 MULTIPOLYGON (((-95.0804 29... 23.1 3.525836 15.26336
## 3 5.5 MULTIPOLYGON (((-94.83092 2... 11.0 3.343465 30.39514
## 4 5.7 MULTIPOLYGON (((-94.90975 2... 14.7 3.465046 23.57174
## 5 5.8 MULTIPOLYGON (((-95.00338 2... 16.7 3.525836 21.11279
## 6 6.0 MULTIPOLYGON (((-94.97188 2... 16.8 3.647416 21.71081
Create a map using quantile breaks of this variable for each year
tm_shape(VHU11)+
tm_polygons(c("VHU11"), title=c("% Vacant Housing Units"), palette="Blues", style="quantile", n=5)+
#tm_format("World", legend.outside=T, title.size =4)+
tm_scale_bar()+
tm_layout(title="Galveston County Percent Vacant Housing Units 2011 - Quantile Breaks", title.size =1, legend.frame = TRUE, title.position = c('left', 'top'))+
tm_compass()
tm_shape(VHU19)+
tm_polygons(c("VHU19"), title=c("% Vacant Housing Units"), palette="Blues", style="quantile", n=5)+
#tm_format("World", legend.outside=T, title.size =4)+
tm_scale_bar()+
tm_layout(title="Galveston County Percent Vacant Housing Units 2019 - Quantile Breaks", title.size =1, legend.frame = TRUE, title.position = c('left', 'top'))+
tm_compass()
Mapping of errors in estimates
Most of the tracts seem to have low error in the estimates.
p1<-tm_shape(VHU11)+
tm_polygons(c("VHU11"), title=c("% Vacant Housing Units"), palette="Reds", style="quantile", n=5)+
#tm_format("World", legend.outside=T, title.size =4)+
tm_scale_bar()+
tm_layout(title="Galveston County Vacant Housing Units Estimates 2011", title.size =1.5, legend.frame = TRUE, title.position = c('right', 'top'))+
tm_compass()
p2<-tm_shape(VHU19)+
tm_polygons(c("VHU19_cv"), title=c("CV Vacant Housing Units"), palette="Reds", style="quantile", n=5)+
#tm_format("World", title="San Antonio Poverty Rate CV", legend.outside=T)+
tm_layout(title="Galveston County Vacant Housing Units CV", title.size =1.5, legend.frame = TRUE, title.position = c('right', 'top'))+
tm_scale_bar()+
tm_compass()
tmap_arrange(p1, p2)
plot(VHU11$VHU11, VHU11$VHU11_cv)
plot(VHU19$VHU19, VHU19$VHU19_cv)
Calculate the differences between the two years, including the test for significance of the differences
mdat<-tigris::geo_join(VHU11, as.data.frame(VHU19), by_sp="GEOID", by_df="GEOID")
## Warning: `group_by_()` is deprecated as of dplyr 0.7.0.
## Please use `group_by()` instead.
## See vignette('programming') for more help
## This warning is displayed once every 8 hours.
## Call `lifecycle::last_warnings()` to see where this warning was generated.
head(mdat)
## Simple feature collection with 6 features and 14 fields
## Active geometry column: geometry.x
## geometry type: POLYGON
## dimension: XY
## bbox: xmin: -95.23308 ymin: 29.29611 xmax: -94.92506 ymax: 29.52631
## geographic CRS: NAD83
## GEOID NAME.x DP04_0003PE.x
## 1 48167720302 Census Tract 7203.02, Galveston County, Texas 0.8
## 2 48167720502 Census Tract 7205.02, Galveston County, Texas 6.0
## 3 48167720501 Census Tract 7205.01, Galveston County, Texas 3.7
## 4 48167721202 Census Tract 7212.02, Galveston County, Texas 2.5
## 5 48167722002 Census Tract 7220.02, Galveston County, Texas 6.7
## 6 48167723502 Census Tract 7235.02, Galveston County, Texas 3.9
## DP04_0003PM.x VHU11 VHU11_er VHU11_cv
## 1 1.4 0.8 0.8510638 106.38298
## 2 4.6 6.0 2.7963526 46.60588
## 3 4.1 3.7 2.4924012 67.36220
## 4 4.2 2.5 2.5531915 102.12766
## 5 5.0 6.7 3.0395137 45.36588
## 6 3.0 3.9 1.8237082 46.76175
## NAME.y DP04_0003PE.y DP04_0003PM.y
## 1 Census Tract 7203.02, Galveston County, Texas 7.1 4.0
## 2 Census Tract 7205.02, Galveston County, Texas 4.1 3.7
## 3 Census Tract 7205.01, Galveston County, Texas 5.5 4.4
## 4 Census Tract 7212.02, Galveston County, Texas 3.6 3.9
## 5 Census Tract 7220.02, Galveston County, Texas 6.7 4.9
## 6 Census Tract 7235.02, Galveston County, Texas 16.4 7.0
## VHU19 VHU19_er VHU19_cv rank geometry.x
## 1 7.1 2.431611 34.24804 1 POLYGON ((-95.23098 29.4754...
## 2 4.1 2.249240 54.85952 1 POLYGON ((-95.12573 29.4685...
## 3 5.5 2.674772 48.63222 1 POLYGON ((-95.13526 29.4973...
## 4 3.6 2.370821 65.85613 1 POLYGON ((-95.06361 29.4849...
## 5 6.7 2.978723 44.45856 1 POLYGON ((-94.93173 29.3952...
## 6 16.4 4.255319 25.94707 1 POLYGON ((-95.08098 29.3434...
## geometry.y
## 1 MULTIPOLYGON (((-95.2318 29...
## 2 MULTIPOLYGON (((-95.12927 2...
## 3 MULTIPOLYGON (((-95.1662 29...
## 4 MULTIPOLYGON (((-95.07501 2...
## 5 MULTIPOLYGON (((-94.93722 2...
## 6 MULTIPOLYGON (((-95.19592 2...
acstest<-function(names,geoid, est1, err1, est2, err2, alpha, yr1, yr2, span){
se1<-err1/qnorm(.90)
se2<-err2/qnorm(.90)
yrs1<-seq(yr1, to=yr1-span)
yrs2<-seq(yr2, to=yr2-span)
C<-mean(yrs2%in%yrs1)
diff<- (est1-est2)
test<-(est1-est2) / (sqrt(1-C)*sqrt((se1^2+se2^2)))
crit<-qnorm(1-alpha/2)
pval<-2*pnorm(abs(test),lower.tail=F)
result<-NULL
result[pval > alpha]<-"insignificant change"
result[pval < alpha & test < 0]<- "significant increase"
result[pval < alpha & test > 0]<-"significant decrease"
data.frame(name=names,geoid=geoid, est1=est1, est2=est2, se1=se1, se2=se2,difference=diff, test=test, result=result, pval=pval)
}
diff1119<-acstest(names = mdat$NAME.x, geoid = mdat$GEOID, est1 = mdat$VHU11, est2 = mdat$VHU19, err1 = mdat$VHU11_er, err2=mdat$VHU19_er,alpha = .1, yr1 = 2011, yr2=2019, span = 5)
head(diff1119)
## name geoid est1 est2 se1
## 1 Census Tract 7203.02, Galveston County, Texas 48167720302 0.8 7.1 0.6640886
## 2 Census Tract 7205.02, Galveston County, Texas 48167720502 6.0 4.1 2.1820055
## 3 Census Tract 7205.01, Galveston County, Texas 48167720501 3.7 5.5 1.9448310
## 4 Census Tract 7212.02, Galveston County, Texas 48167721202 2.5 3.6 1.9922659
## 5 Census Tract 7220.02, Galveston County, Texas 48167722002 6.7 6.7 2.3717451
## 6 Census Tract 7235.02, Galveston County, Texas 48167723502 3.9 16.4 1.4230471
## se2 difference test result pval
## 1 1.897396 -6.3 -3.1339306 significant increase 0.0017248166
## 2 1.755091 1.9 0.6785068 insignificant change 0.4974504207
## 3 2.087136 -1.8 -0.6309577 insignificant change 0.5280681887
## 4 1.849961 -1.1 -0.4046010 insignificant change 0.6857708000
## 5 2.324310 0.0 0.0000000 insignificant change 1.0000000000
## 6 3.320443 -12.5 -3.4601745 significant increase 0.0005398254
table(diff1119$result)
##
## insignificant change significant decrease significant increase
## 40 11 14
acs_merge<-left_join(mdat, diff1119, by=c("GEOID"="geoid"))
tmap_mode("plot")
## tmap mode set to plotting
p1<-tm_shape(acs_merge)+
tm_polygons(c("VHU11"), title=c("% Vacant Housing Units 2011"), palette="Blues", style="quantile", n=5)+
#tm_format("World", legend.outside=T, title.size =4)+
tm_scale_bar()+
tm_layout(title="Galveston County Percent Vacant Housing Units 2011", title.size =1.5, legend.frame = TRUE, title.position = c('right', 'top'))+
tm_compass()
p2<-tm_shape(acs_merge)+
tm_polygons(c("VHU19"), title=c("% Vacant Housing Units 2019"), palette="Blues", style="quantile", n=5)+
#tm_format("World", title="Galveston County Percent Vacant Housing Units CV", legend.outside=T)+
tm_layout(title="Galveston County Percent Vacant Housing Units 2019", title.size =1.5, legend.frame = TRUE, title.position = c('right', 'top'))+
tm_scale_bar()+
tm_compass()
p3 <- tm_shape(acs_merge)+
tm_polygons(c("result"), title=c("Changes"), palette = "Dark2")+
#tm_format("World", title="Galveston County Percent Vacant Housing Units CV", legend.outside=T)+
tm_layout(title="Galveston County Percent Vacant Housing Units Estimate Changes", title.size =1.5, legend.frame = TRUE, title.position = c('right', 'top'))+
tm_scale_bar()+
tm_compass()
tmap_arrange(p1, p2, p3)
The purple areas of the map of Galveston County shows that the census tracts with a significant increase in percent of vacant housing units are mostly on the west side of Interstate 45 on the mainland and the west side of the island.