sysuse lifeexp, clear 
gen loggnp = log10(gnppc)
label var loggnp "Log base 10 of GNP per capita"

#delimit ;

scatter lexp loggnp, yscale(alt) xscale(alt) xlabel(, grid gmax) saving(yx)

twoway histogram lexp, fraction xscale(alt reverse) horiz saving(hy)

twoway histogram loggnp, fraction yscale(alt reverse) 
  ylabel(,nogrid) xlabel(,grid gmax) saving(hx)
  ;

graph combine hy.gph yx.gph hx.gph, hole(3) 
  imargin(0 0 0 0) graphregion(margin(l=22 r=22))
  title("Life expectancy at birth vs. GNP per capita")
  note("Source:  1998 data from The World Bank Group")
  ;
#delimit cr