[Radiance-general] Site Standard Meridian argument in genrsky

[Axel Jacobs]

Hi Vaib,

> I just wish to confirm about the Site Standard Meridian (-m) argument
> for genrsky. Is it the following:
>
> Local longitude of Standard Time Meridian (LSTM):
> LSTM = 15 deg x (Longitude/15 deg)_round to integer

What you are describing is a special case that is true for most, but not 
all, time zones.

Most time zones in Radiance notation are given in multiples of 15 
degrees.  Exceptions to this are the countries marked on this map
http://www.icsm.gov.au/mapping/images/time_zones.jpg
with a star.

Countries that have a TZ of GMT +/- X.5 hrs or -(X*15) + 7.5 deg include:
- India
- a bit of Australia
- Iran
(there are more...)

Finally, there is Nepal which is at GMT +5:45 hrs or -5.75*15 = -86.25 
deg in Radiance notation.

In other words: the 'round to integer' part of your equation is correct 
in most, but not all, cases.  You might end up with a floating point 
number if your project is located in exotic places.

FYI: This integer bug existed in epw2wea which just recently made it 
into Radiance HEAD. It was fixed just before Christmas.

Regards

Axel