Re: Documentation fix regarding atan2

Thanks.

On 9/15/07, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>
>
> Change made. Thanks. Your documentation changes can be viewed in five
> minutes using links on the developer's page,
> http://www.postgresql.org/developer/testing.
>
>
> ---------------------------------------------------------------------------
>
>
> Andrew Maclean wrote:
> > In Table 9.4 of the documentation atan2 is described as follows:
> > atan2(*x*, *y*) inverse tangent of *x*/*y*
> >
> > I am sure it should read as:
> > atan2(*y*, x) inverse tangent of y/x
> >
> > This looks to be the standard C++/c atan2(y,x) function.
> >
> > You can easily test this:
> > If y = 2, x = 1, then degrees(atan(y/x)) =63.4 but if we proceed
> according
> > to the documentation; degrees(atan2(x,y))=degrees(atan2(1,2))=25.6 which
> is
> > not the same as degrees(atan(y/x)).
> > So it must be degrees(atan2(y,x))=degrees(atan2(2,1))=63.4.
> >
> >
> > Thanks
> > Andrew
> >
> > --
> > ___________________________________________
> > Andrew J. P. Maclean
> > Centre for Autonomous Systems
> > The Rose Street Building J04
> > The University of Sydney 2006 NSW
> > AUSTRALIA
> > Ph: +61 2 9351 3283
> > Fax: +61 2 9351 7474
> > URL: http://www.acfr.usyd.edu.au/
> > ___________________________________________
>
> --
> Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
> EnterpriseDB http://www.enterprisedb.com
>
> + If your life is a hard drive, Christ can be your backup. +
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--
___________________________________________
Andrew J. P. Maclean
Centre for Autonomous Systems
The Rose Street Building J04
The University of Sydney 2006 NSW
AUSTRALIA
Ph: +61 2 9351 3283
Fax: +61 2 9351 7474
URL: http://www.acfr.usyd.edu.au/
___________________________________________