Re: st: Formula/algorithm Stata uses to calculate default axis ranges and tick marks?

["Roger B. Newson" <r.newson@imperial.ac.uk>]

I cannot speak for StataCorp, or specify their formulas. However, I have 
written an alternative package -regaxis-, which can be downloaded from 
SSC, which has 2 modules -logaxis- and -regaxis- for calculating regular 
logarithmic and linear axis scales, respectively. I wrote this package 
because I was not always satisfied with the defaults provided by Stata 
graphics. The online help for -regaxis- describes (verbally) the 
algorithms used there.
I hope this is helpful.

Best wishes

Roger


Roger B Newson BSc MSc DPhil
Lecturer in Medical Statistics
Respiratory Epidemiology and Public Health Group
National Heart and Lung Institute
Imperial College London
Royal Brompton Campus
Room 33, Emmanuel Kaye Building
1B Manresa Road
London SW3 6LR
UNITED KINGDOM
Tel: +44 (0)20 7352 8121 ext 3381
Fax: +44 (0)20 7351 8322
Email: r.newson@imperial.ac.uk
Web page: http://www.imperial.ac.uk/nhli/r.newson/
Departmental Web page:
http://www1.imperial.ac.uk/medicine/about/divisions/nhli/respiration/popgenetics/reph/

Opinions expressed are those of the author, not of the institution.

On 06/10/2012 20:51, Nick Cox wrote:
> The methodology for nice numbers is broadly similar to that described in
>
> STB-25  dm28  . . .  Calculate nice numbers for labeling or drawing grid lines
>          (help nicenum if installed) . . . . . . . . . . . . . . . J. W. Hardin
>          5/95    pp.2--3; STB Reprints Vol 5, pp.19--20
>
> Otherwise I doubt that there is any on-line documentation of the kind you seek.
>
> Nick
>
> On Sat, Oct 6, 2012 at 7:46 PM, Michael Stepner
> <michaelstepner@gmail.com> wrote:
>
> > I'm trying to find a description of the formula or algorithm Stata
> > uses to set the default look of a scatter plot's axes: how it chooses
> > the default range and tick marks.  I've searched online and in the
> > Stata manual, but haven't found any details.  I've read that Stata
> > chooses approximately 5 "nice values" for the tick marks, but haven't
> > found any indication of how those "nice values" are selected.
> >
> > If anyone could point me to a detailed description of the methodology
> > for selecting the nice defaults, it would be greatly appreciated!
> > Even if it's just pointing me to some code where these defaults are
> > calculated and implemented, that would be a great help.
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/faqs/resources/statalist-faq/
> *   http://www.ats.ucla.edu/stat/stata/
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/