Supply demand graph

[Chrystelle Rebelo Ferreira]

Dear all,

Sorry for my beginner level with stata, I'm estimating the supply and demand in the sugar sector, I don't have simultaneity so I can do a linear regression. For the supply, I have this regression: reg prod_beet nbr_growers ha_beet yield_beet sugar_content price_beet.
I wanted to represent this regression on a graph with on the x-axis the prod_beet and on the y-axis price_beet (see picture below)

Can someone help me please?

[Jared Greathouse]

tw (function x + 1, lcol("12 10 0")) ///
(function -x + 1, lcol("237 91 154")), ///
legend(off) text(1 .9 "S") ///
text(1 .1 "D") ///
xti(Q{sub:D}) ///
yti("P (Price)") ///
ti({bf:Supply and Demand}, pos(11)) ///
note("{&copy} 2013, Encylopædia Britannica", size(medium)) ///
xlabel(, nolabels noticks nogrid) ///
ylabel(, nolabels noticks nogrid) ///
yscale(lcolor(navy) lwidth(medium)) ///
xscale(lcolor(navy) lwidth(medium))

Perhaps Nick Cox or Maarten Buis May comment on the addition of lines?