Hi,

I would like to generate one histogram which have three graphs covering on the others. The three graphs were supposed to cover the earlier graphs if they locate at the same position. However, some bars were placed perfectly, some were not with some shifting. For example, there were two blue bars (around May 2016 and May 2018) on the same date of the red/ gray bars and the very small shifting of blue made them show some red color behind. In other situations, some blue bars (e.g., 1/3) could cover perfectly and some (e.g., 2/3) could not.

All the numbers and values are just from made-up data for clarifying my questions.

The syntax for the 1st combined histogram is listed here:
twoway ///
(histogram date if (outcome==3 | outcome ==2 | outcome ==1), disc freq fcolor(gray) lcolor(black) lwidth(vvthin) width(8) gap(0) ) || ///
(histogram date if (outcome==3 | outcome ==2), disc freq fcolor(blue) lcolor(black) lwidth(vvthin) width(8) gap(0) ) || ///
(histogram date if (outcome==3 ), disc freq fcolor(red) lcolor(black) lwidth(vvthin) width(8) gap(0) ) ///
, ///
ylab(1(1)5) xtitle("First Diagnosis Date") xmtick(`minday0'(30)`maxday0') ytitle("Number of Cases") ///
xlabel(`minday0'(60)`maxday0', format(%d) labsize(small) angle(45)) ///
legend(label (1 "All Cases") label(2 "Car Related") label(3 "Bike Related") pos(6)) plotregion(margin(zero)) ///
title("Count Curve, N=2") subtitle("Summarized cases dates from: `minday1' to `maxday1'") note("Chart Produced: `c_date'")

I have spent several days on this and could not figure out why some are good while some are not in one graph. I would appreciate any help you could offer. Thank you very much.

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