Chinh Nguyen and Vince Wiggins of StataCorp provided a solution in the
post below.
http://www.stata.com/statalist/archive/2009-11/msg01093.html
For a straight line drawn with -twoway function- the -n(2)- option
should be added.
. twoway (scatter y x, connect(l) clwidth(thin)) (function y=x+1,
range(0 100) n(2) lwidth(thin)), aspect(1)
Friedrich
On Thu, Nov 19, 2009 at 12:05 PM, G Livesey <[email protected]> wrote:
> Dear All,
>
> I confirm Friedrich observation for my Windows system, and note that:
>
> 1) the connect line has a somewhat similar appearance, but steps in one
> direction only at a lower regular frequency (unrelated to screen pixels).
> 2) the function line wavers at higher but irregular frequency (also
> unrelated to pixels).
>
> Such appears at all sizes of the graph window.
>
> Such in STATA 11 SE, 21st Oct installation and updates, on MS Win XP (ado
> versions noted below signature line).
>
>
> I would support technical examination of this issue.
>
> Geoff. Livesey.
>
> Note also:
>
> which twoway
> C:\Program Files\Stata11\ado\base\t\twoway.ado
> *! version 1.2.0 16apr2007
>
> which scatter
> C:\Program Files\Stata11\ado\base\s\scatter.ado
> *! version 1.2.0 16apr2007
>
> which range
> C:\Program Files\Stata11\ado\base\r\range.ado
> *! version 2.1.1 13dec1998
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Friedrich Huebler
> Sent: 19 November 2009 16:03
> To: [email protected]
> Subject: Re: st: graphics complaints (Windows too)
>
>
> Dave wrote about Stata on OS X but I have a similar observation about Stata
> on Windows, specifically concerning -twoway function-.
>
> A y=x line drawn with -twoway function- is not as straight as a line drawn
> with -twoway scatter, connect-. The difference can be illustrated with the
> following commands.
>
> . clear
> . set obs 2
> . gen x = .
> . replace x = 0 in 1
> . replace x = 100 in 2
> . gen y = .
> . replace y = 0 in 1
> . replace y = 100 in 2
> . twoway (scatter y x, connect(l) clwidth(thin)) (function y=x+1, range(0
> 100) lwidth(thin)), aspect(1)
>
> The -function- line is uneven and can indeed be described as "shocked with
> electricity", to use Dave's words. Is it possible to draw a
> -function- line as straight as a -scatter, connect- line?
>
> Friedrich
>
> On Wed, Nov 18, 2009 at 3:57 PM, Airey, David C <[email protected]>
> wrote:
>> . sysuse auto
>> (1978 Automobile Data)
>>
>> . scatter weight length, ms(oh) // small o
>>
>> never renders well on my system, and copying the graph preserves the
>> oblong symbols
>>
>> . scatter weight length, ms(Oh) // large O
>>
>> doesn't show the complaint
>>
>> I sent you off list the horrible rendering of a graph twoway function
>> (y=x). Looked like someone shocked it with electricity.
>>
>> -Dave
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