From: "Kyrre Nygård" <kyrreny@...>
Date: 2007-08-16T06:27:14+09:00
Subject: Re: Any Muslims around?

Thanks a lot Ken, and the same to you guys, Ronald and John.

I'll report back to base once I got something.

All the best,
Kyrre Nygård

Ken Bloom wrote:
> On Tue, 14 Aug 2007 20:50:02 +0900, Kyrre Nygård wrote:
>
>   
>> Just wondering if any Muslims have gotten around to making a Ruby script
>> that like plays a sound or something when it's time for prayer.
>>
>> Thanks,
>> Kyrre Nygård
>>     
>
> Would this help? I use it as part of a suite of scripts for computing 
> times that Orthodox Jews use to compute times for prayer. The algorithm 
> comes from the US Naval Observatory's Almanac for Computers.
>
> --Ken
>
>
>
> require 'date'
> require 'mathn'
>
> #methods stolen from ruby-doc.org
> class Date
>    def to_datetime() DateTime.new0(self.class.jd_to_ajd(jd, 0, 0), @of, 
> @sg) end
>    def to_date() self end
>    def to_time() Time.local(year, mon, mday) end
> end
> class DateTime
>   def to_date() Date.new0(self.class.jd_to_ajd(jd, 0, 0), 0, @sg) end
>   def to_datetime() self end
>   def to_time
>     d = new_offset(0)
>     d.instance_eval do
>       Time.utc(year, mon, mday, hour, min, sec,
>                (sec_fraction * 86400000000).to_i)
>     end.
>         getlocal
>   end  
> end
>
> #end stolen
>
> def dms(degrees,minutes,seconds)
>    degrees+minutes/60+seconds/60/60
> end
>
> module Sunrise
>    include Math
>    class Location
>       attr_accessor :latitude, :longitude, :offset
>       def initialize(latitude,longitude)
> 	 @latitude,@longitude=latitude,longitude
>       end
>    end
>
>    def toRad(degrees)
>       degrees*PI/180
>    end
>
>    def toDeg(radians)
>       radians*180/PI
>    end
>
>    def sun_rise_set(which,date,location,zenith)
>       #step 1: first calculate the day of the year
>       n=date.yday
>
>       #step 2: convert the longitude to hour value and calculate an 
> approximate time
>       lngHour=location.longitude/15
>       t=n+ ((6-lngHour)/24) if which==:sunrise
>       t=n+ ((18-lngHour)/24) if which==:sunset
>
>       #step 3: calculate the sun's mean anomaly
>       m=(0.9856 * t) - 3.289
>
>       #step 4: calculate the sun's true longitude
>       l=  (m+(1.1916 * sin(toRad(m))) + (0.020 * sin(toRad(2*m))) + 
> 282.634) % 360
>
>       #step 5a: calculate the sun's right ascension
>       ra = toDeg(atan(0.91764 * tan(toRad(l)))) % 360
>       ###step 5b: right ascension value needs to be in the same quadrant 
> as L
>       lquadrant = (l/90).floor*90
>       raquadrant = (ra/90).floor*90
>       ra=ra+(lquadrant-raquadrant)
>
>       #step 5c: right ascension value needs to be converted into hours
>       ra/=15
>
>       #step 6: calculate the sun's declination
>       sinDec = 0.39782 * sin(toRad(l))
>       cosDec = cos(asin(sinDec))
>       #step 7a: calculate the sun's local hour angle
>       cosH = (cos(toRad(zenith)) - (sinDec * sin(toRad
> (location.latitude)))) / (cosDec * cos(toRad(location.latitude)))
>
>       return nil if (not (-1..1).include? cosH)
>
>       #step 7b: finish calculating H and convert into hours
>       h = (360 - toDeg(acos(cosH)))/15 if which==:sunrise
>       h = (toDeg(acos(cosH)))/15       if which==:sunset
>       #step 8: calculate local mean time
>       t = h + ra - (0.06571 * t) - 6.622
>       t %=24
>       #step 9: convert to UTC
>       return date.to_datetime+(t - lngHour)/24
>    end
>
>    private :sun_rise_set
>
>    def sunrise(date,location,zenith=90.8333)
>       sun_rise_set :sunrise,date,location,zenith
>    end
>    def sunset(date,location,zenith=90.8333)
>       sun_rise_set :sunset,date,location,zenith
>    end
> end
>
>
>