Error with Sunrise.pm

[clarissa1996]

Hi all,

I use the perl module Sunrise.pm. All works perfectly.
But I have a problem with a single date (this is very strange !!).

The following perl script:

($sunrise, $sunset) = sunrise(2005, 3, 20, -7.4, 46.9, 0, 0, -6);

... generate the following error:

Sun never sets!!

(Note: $sunrise and $sunset = 00:37)

Input parameters seems me correct.
Longitude and latitude are of the city of Bern (Switzerland).

I appreciate very much if someone can help me.

Best Regards.

Clarissa

 

[effennel]

Aaah! Where the sun never sets...

Could it be this?

Eastern longitude is entered as a positive number
Western longitude is entered as a negative number
Northern latitude is entered as a positive number
Southern latitude is entered as a negative number

FNL

 

[clarissa1996]

Hi Effennel,

thanks for your help.
I have inserted the correct sign (+7.4).
The error is disappears but the sunrise and sunset values for 3/20/2005 are not calculated correctly.

3/19/2005 Sunrise: 06:06, Sunset: 19:10
3/20/2005 Sunrise: 06:49, Sunset: 18:26
3/21/2005 Sunrise: 05:59, Sunset: 19:16

Another question:
-7.4 +46.9 is somewhere north of Spain.
Why the program do not works correctly for this place ?

Thanks in advance. Clarissa

 

[effennel]

Clarissa,

What about other dates?

Regarding the other Q?:
This is how I understand the + and - in front of the (latitude,longitude):

Greenwich
|
(+,-) | (+,+)
|
----------------------------------------- equator
|
(-,-) | (-,+)
|

So I think north of Spain in (+,+)...

FNL

 

[clarissa1996]

Hi Effennel,

Question 1:
Until now I have found the error only for date 3/20/2005. Also for latitude=0 and longitude=0 the values of sunrise and sunset for the dates 19-20-21 March 2005 are not "linear". The problem is always day 3/20/2005.
Maybe you can calculate the sunrise/sunset for your latutine/longitudine for the days 19-20-21 March 2005 and report the results.

Question 2:
Switzerland is east of Greenwich (+,+).
Spain is west of Greenwich (+,-).
... However it remains the problem that with some (good) coordinates the program returns an error


Best Regards.

Clarissa