Questions about epw2wea

radiance-general
1

Hello, experts.
I have a question about the epw2wea program.

I converted with the following command and the sign of the longitude in the wea file was reversed.

>epw2wea TOKYO.epw TOKYO.wea
place TOKYO_JPN
latitude 35.69
longitude -139.76
time_zone -135.00
site_elevation 6.0
weather_data_file_units 1

The first line of the EPW file shows that the longitude is "+"139.76.
LOCATION,TOKYO,TOKYO,JPN,Expanded AMeDAS Weather Data R2010,3630,35.69,139.76,9.0,6.0

Does anyone know why this is happening?
Thanks in advance.

2

Hi Matu,

EPW and Radiance have different conventions as what a positive/negative longitude is.

From the Radiance gensky man page:

“The site longitude is lon degrees west. (Use negative angle for east longitude.)”

So epw2wea simpliy flips the sign so that the wea file conforms to Radiance conventions

Cheers

Axel

1 Like
3

I understand!

Thanks for your reply!