Re: st: graph: how to draw 45 degree reference line

[<Stefan.Gawrich@hlpug.hessen.de>]

Hi Statalisters,

Friedhelm Huebler wrote: 

-line price price- is easy but depending on the resolution of the
display the line will not appear entirely straight. The appearance
also depends on how the data are sorted. -function- with the option
n(2) yields a cleaner graph. The setting of the range can be
automated.

. sysuse auto, clear
. sum price, meanonly
. local xmin = r(min)
. local xmax = r(max)
. twoway (scatter weight price) (function y=x, range(`xmin' `xmax')
n(2)), aspect(1)


****

I think, - twoway lfit - is best in this case:

// Line from min to max:
. twoway scatter weight price || lfit price price, aspect(1) range(. .) n(2)

// Line from 0 to max:
. twoway scatter weight price || lfit price price, aspect(1) range(0 .) n(2)

The "range" option of - lfit - is more versatile. 
Friedhelm Hueblers "n(2)" trick works with - lfit - 


Regards

Stefan Gawrich
HLPUG
Dillenburg
Germany




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