st: [Graphics] how to set the length of an axis?

[Antoine Terracol <terracol@univ-paris1.fr>]

Dear _all,

I was asked if I could reproduced a graphic like 
http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=109
in Stata.

Using nlswork.dta, I was able to produce the graph whose code is pasted 
below.

As you can see, the years are not evenly spaced on the x-axis. In 
particular, the part between "1" and "2" is much smaller than the rest.

I understand that, in fact, the total width of the sub graphs are all 
equal, and that the visual difference is due to the presence of the y 
axis and its legend in the first sub-graph.

Is there a way to set the length of the axis in the first sub graph, or, 
alternatively, to produce a graph with just the y-axis in such a way 
that it would look nice?

Best,
Antoine

/*--------------------------------------------*/
clear
set scheme s2mono
webuse nlswork.dta, clear
g wage=exp(ln_wage)
su wage, de
drop if wage>r(p99)
egen t=group(year)
g ti=t+runiform()
g ti2=ti^2
g ti3=ti^3
qreg wage ti ti2 ti3
predict med
qreg wage ti ti2 ti3 , quantile(.95)
predict q95
qreg wage ti ti2 ti3 , quantile(.05)
predict q5

twoway (hist wage if t==1 , fcolor(gs14) plotr(m(zero)) 
graphregion(margin(zero) color(white)) xlabel(0 "1") xtitle("") 
ylabel(0(5)20, grid gmin gmax)  horiz) (line med q95 q5 ti if t==1, sort 
xaxis(2) yaxis(2) ylabel(0(5)20, axis(2)) lcolor(black black black) 
lwidth(thick thick thick) lpattern(solid solid solid) xscale(off 
axis(2)) yscale(off axis(2)) plotr(m(zero))) , legend(off)  saving(a, 
replace)
local list "a.gph"

local t=2
while `t'<=15 {
    twoway (hist wage if t==`t', fcolor(gs14) plotr(m(zero)) 
graphregion(margin(zero) color(white)) xlabel(0 "`t'") xtitle("") 
yscale(off)  xtitle("") ylabel(0(5)20 , grid gmin gmax)  horiz) (line 
med q95 q5 ti if t==`t', sort xaxis(2) yaxis(2) ylabel(0(5)20, axis(2)) 
lcolor(black black black) lwidth(thick thick thick) lpattern(solid solid 
solid) xscale(off axis(2)) yscale(off axis(2)) ) , legend(off) 
saving(a`t', replace)
	local list "`list' a`t'.gph"
	local t=`t'+1
}
graph combine `list', imargin(0 0 0 0) row(1) graphregion(color(white)) 
note(t, pos(6))
/*--------------------------------------------------*/

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