Small Area Estimation - Sampling Spatial Units for Agricultural Surveys - page 273

Fig. 11.1 Map of the selected points and definition of SAs
> par(mar ¼ c(1,1,1,1),xaxs ¼ "i",yaxs ¼ "i")
> par(mar ¼ c(1,1,1,1),xaxs ¼ "i",yaxs ¼ "i")
> plot(framepop$xc,framepop$yc, axes ¼ F,cex ¼ 0.5,pch ¼ 19, xlim ¼ c(0,1),
+ ylim ¼ c(0,1))
> points(framesrs$xc,framesrs$yc, pch ¼ 1, cex ¼ 2)
> abline(h ¼ 1/3,lty ¼ 2,lwd ¼ 2)
> abline(h¼2/3,lty¼2,lwd¼2)
> abline(v¼1/3,lty¼2,lwd¼2)
> abline(v¼2/3,lty¼2,lwd¼2)
> box()
Note that in all the examples in this chapter we are estimating the mean, for
practical reasons. It is obviously straightforward to derive estimates of the total for
each SA. Using the survey package, the HT direct estimate for a single SA
(denoted as 11) can be calculated as follows.
> dom1srs < - subset(dsrs,coddom ¼¼ 11)
> domdir < - svymean(~yobs,dom1srs)
> domdir
mean SE
yobs 80.126 4.8138