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2006-Jan-22 23:34 UTC

[Rails] calculate users age

i know it''s probably really simple, how do i work out
someone''s age if i
have their d.o.b. stored as a date in my db.

cheers

-- 
Posted via http://www.ruby-forum.com/.

Joseph Chan

2006-Jan-23 02:36 UTC

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[Rails] calculate users age

Depending on your database, how about doing something with the datediff() or
similar function?    eg: for Postgresql:

select (current_timestamp-dob) / 365.25 from users

I''m sure you could

On 1/23/06, pd <pd@gmail.com> wrote:>
> i know it''s probably really simple, how do i work out
someone''s age if i
> have their d.o.b. stored as a date in my db.
>
> cheers
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
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Pat Maddox

2006-Jan-23 02:45 UTC

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[Rails] calculate users age

irb(main):001:0> require ''date''
=> true
irb(main):002:0> bday = Date.new(1985, 7, 24)
=> #<Date: 4892541/2,0,2299161>
irb(main):003:0> age = (Date.today - bday).to_i / 365
=> 20


This is ruby, so there''s probably a better way.  There should be some
slick way of doing it like
bday.years.until(Date.today)  # This does not work.  But I think it''d
be cool if it did :)

Pat




On 1/22/06, pd <pd@gmail.com> wrote:> i know it''s probably really simple, how do i work out
someone''s age if i
> have their d.o.b. stored as a date in my db.
>
> cheers
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

Alexey Verkhovsky

2006-Jan-23 04:33 UTC

head link

[Rails] calculate users age

Two things to think about:

1. In Rails, database is for stoiring raw data, not for calculations.
There is nothing wrong in using it for calculations when you have some
good reason to do so, but by default you shouldn''t do it.

2. days/365, as well as days/365.25 are both approximations (the former
is wrong more often than the latter). Sure, we can do better than that!

So, how about below?

Alex

require ''test/unit''
class BirthdayTest < Test::Unit::TestCase

  def test_simple
    assert_equal 100, age(Date.new(1905, 1, 1), Date.new(2005, 1, 1))
  end

  def test_age_born_this_year_is_zero
    assert_equal 0, age(Date.new(2005, 1, 1), Date.new(2005, 12, 31))
    assert_equal 1, age(Date.new(2005, 1, 1), Date.new(2006, 1, 1))
  end

  def test_doesnt_like_negative_age
    birthdate = Date.new(2005, 1, 2)
    day_before_birthdate = birthdate - 1
    assert_raises(RuntimeError) { age(birthdate,  day_before_birthdate) }
  end

  def test_works_well_when_birthday_already_passed_this_year
    assert_equal 9, age(Date.new(1990, 2, 2), Date.new(2000, 2, 1))
    assert_equal 10, age(Date.new(1990, 2, 2), Date.new(2000, 2, 2))
  end

  def test_handles_feb_29
    assert_equal 4, age(Date.new(2000, 2, 29), Date.new(2005, 2, 28))
    assert_equal 5, age(Date.new(2000, 2, 29), Date.new(2005, 3, 1))
  end

  def test_handles_many_years
    assert_equal 6000, age(Date.new(-3000, 1, 1), Date.new(3000, 12, 31))
  end

end

def age(birthdate, now)
  raise "Birthdate (#{birthdate.strftime(''%Y-%m-%d'')}) is
after now
(#{now.strftime(''%Y-%m-%d'')})" if birthdate > now

  had_birthday_passed_this_year = (now.month * 100 + now.day >birthdate.month
* 100 + birthdate.day)
  if had_birthday_passed_this_year
    now.year - birthdate.year
  else
    now.year - birthdate.year - 1
  end
end

2006-Jan-23 14:45 UTC

head link

[Rails] calculate users age

Weird, I was just writing something like this in the course of
learning ruby.  I doubt you''ll learn anything by just posting a random
question and expecting an answer.  You should at least give it a stab.

Hopefully, a more experienced ruby programmer will give me advice to
improve my code.


Here''s my attempt:

birthday.rb code

require "time"

class Birthday

#This can be slimmed down considerably
#but I thought it might be useful to keep them all separate

def initialize(birth_month, birth_date, birth_year)
  @birth_month = birth_month
  @birth_date = birth_date
  @birth_year = birth_year
end

#This puts the birthday in a format that can be manipulated
def bday
  bday = @birth_month + "/" + @birth_date + "/" +
@birth_year
  Time.parse(bday)
end

#This will round off the age
def age
  age = ((Time.now - self.bday)/60/60/24/365).to_i
end

end


If you load this from irb using irb> load ''birthday.rb''

you can put in

irb>    john = Birthday.new("1", "1", "1984")
irb>    john.age

Norman Timmler

2006-Jan-23 16:06 UTC

head link

[Rails] calculate users age

Am Sonntag, den 22.01.2006, 21:33 -0700 schrieb Alexey Verkhovsky:
> def age(birthdate, now)
>   raise "Birthdate
(#{birthdate.strftime(''%Y-%m-%d'')}) is after now
> (#{now.strftime(''%Y-%m-%d'')})" if birthdate > now
> 
>   had_birthday_passed_this_year = (now.month * 100 + now.day >>
birthdate.month * 100 + birthdate.day)
>   if had_birthday_passed_this_year
>     now.year - birthdate.year
>   else
>     now.year - birthdate.year - 1
>   end
> end
I made a small enhancement for the Date class from it:

class date
  def age(today = self.class.today)
    today.year - year - ((today.month * 100 + today.day >= month * 100 +
day) ? 0 : 1)
  end
end

If no attribute is passed, it calculates the age for today. You can pass
a Date object to calculate the age on a specific date.

-- 
Norman Timmler

http://blog.inlet-media.de

Paul Barry

2006-Jan-24 06:02 UTC

head link

[Rails] calculate users age

When I copy the text and save it into a file called BirthdayTest.rb and then
try to run it, I get these errors.  It seems like Date.new doesn''t like
having 3 arguments.  I am using Ruby 1.8.2 on Win XP.  Any idea why this is?

Loaded suite BirthdayTest
Started
EEEEEE
Finished in 0.0 seconds.

  1) Error:
test_age_born_this_year_is_zero(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:9:in `initialize''
    BirthdayTest.rb:9:in `new''
    BirthdayTest.rb:9:in `test_age_born_this_year_is_zero''

  2) Error:
test_doesnt_like_negative_age(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:14:in `initialize''
    BirthdayTest.rb:14:in `new''
    BirthdayTest.rb:14:in `test_doesnt_like_negative_age''

  3) Error:
test_handles_feb_29(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:25:in `initialize''
    BirthdayTest.rb:25:in `new''
    BirthdayTest.rb:25:in `test_handles_feb_29''

  4) Error:
test_handles_many_years(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:30:in `initialize''
    BirthdayTest.rb:30:in `new''
    BirthdayTest.rb:30:in `test_handles_many_years''

  5) Error:
test_simple(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:5:in `initialize''
    BirthdayTest.rb:5:in `new''
    BirthdayTest.rb:5:in `test_simple''

  6) Error:
test_works_well_when_birthday_already_passed_this_year(BirthdayTest):
ArgumentError: wrong number of arguments (3 for 0)
    BirthdayTest.rb:20:in `initialize''
    BirthdayTest.rb:20:in `new''
    BirthdayTest.rb:20:in
`test_works_well_when_birthday_already_passed_this_year''

6 tests, 0 assertions, 0 failures, 6 errors

On 1/22/06, Alexey Verkhovsky <alex@verk.info>
wrote:>
> Two things to think about:
>
> 1. In Rails, database is for stoiring raw data, not for calculations.
> There is nothing wrong in using it for calculations when you have some
> good reason to do so, but by default you shouldn''t do it.
>
> 2. days/365, as well as days/365.25 are both approximations (the former
> is wrong more often than the latter). Sure, we can do better than that!
>
> So, how about below?
>
> Alex
>
> require ''test/unit''
> class BirthdayTest < Test::Unit::TestCase
>
>   def test_simple
>     assert_equal 100, age(Date.new(1905, 1, 1), Date.new(2005, 1, 1))
>   end
>
>   def test_age_born_this_year_is_zero
>     assert_equal 0, age(Date.new(2005, 1, 1), Date.new(2005, 12, 31))
>     assert_equal 1, age(Date.new(2005, 1, 1), Date.new(2006, 1, 1))
>   end
>
>   def test_doesnt_like_negative_age
>     birthdate = Date.new(2005, 1, 2)
>     day_before_birthdate = birthdate - 1
>     assert_raises(RuntimeError) { age(birthdate,  day_before_birthdate) }
>   end
>
>   def test_works_well_when_birthday_already_passed_this_year
>     assert_equal 9, age(Date.new(1990, 2, 2), Date.new(2000, 2, 1))
>     assert_equal 10, age(Date.new(1990, 2, 2), Date.new(2000, 2, 2))
>   end
>
>   def test_handles_feb_29
>     assert_equal 4, age(Date.new(2000, 2, 29), Date.new(2005, 2, 28))
>     assert_equal 5, age(Date.new(2000, 2, 29), Date.new(2005, 3, 1))
>   end
>
>   def test_handles_many_years
>     assert_equal 6000, age(Date.new(-3000, 1, 1), Date.new(3000, 12, 31))
>   end
>
> end
>
> def age(birthdate, now)
>   raise "Birthdate
(#{birthdate.strftime(''%Y-%m-%d'')}) is after now
> (#{now.strftime(''%Y-%m-%d'')})" if birthdate > now
>
>   had_birthday_passed_this_year = (now.month * 100 + now.day >>
birthdate.month * 100 + birthdate.day)
>   if had_birthday_passed_this_year
>     now.year - birthdate.year
>   else
>     now.year - birthdate.year - 1
>   end
> end
>
>
>
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
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Alexey Verkhovsky

2006-Jan-24 06:09 UTC

head link

[Rails] calculate users age

Paul Barry wrote:
> When I copy the text and save it into a file called BirthdayTest.rb 
> and then try to run it, I get these errors.  It seems like Date.new 
> doesn''t like having 3 arguments.  I am using Ruby 1.8.2 on Win XP.
> Any idea why this is?
Hmm... worksforme (TM)

C:\eclipse\workspace\i2>ruby -v
ruby 1.8.2 (2004-12-25) [i386-mswin32]

C:\eclipse\workspace\i2>irb
irb(main):001:0> Date.new(2000, 1, 1)
=> #<Date: 4903089/2,0,2299161>

C:\>age
Loaded suite C:/age
Started
......
Finished in 0.031 seconds.

6 tests, 9 assertions, 0 failures, 0 errors

Alex

Paul Barry

2006-Jan-24 06:17 UTC

head link

[Rails] calculate users age

Weird...

E:\home\pbarry\projects\rails>ruby -v
ruby 1.8.2 (2004-12-25) [i386-mswin32]

E:\home\pbarry\projects\rails>irb
irb(main):001:0> Date.new(2000,1,1)
ArgumentError: wrong number of arguments (3 for 0)
        from (irb):1:in `initialize''
        from (irb):1:in `new''
        from (irb):1

On 1/24/06, Alexey Verkhovsky <alex@verk.info>
wrote:>
> Paul Barry wrote:
>
> > When I copy the text and save it into a file called BirthdayTest.rb
> > and then try to run it, I get these errors.  It seems like Date.new
> > doesn''t like having 3 arguments.  I am using Ruby 1.8.2 on
Win XP.
> > Any idea why this is?
>
> Hmm... worksforme (TM)
>
> C:\eclipse\workspace\i2>ruby -v
> ruby 1.8.2 (2004-12-25) [i386-mswin32]
>
> C:\eclipse\workspace\i2>irb
> irb(main):001:0> Date.new(2000, 1, 1)
> => #<Date: 4903089/2,0,2299161>
>
> C:\>age
> Loaded suite C:/age
> Started
> ......
> Finished in 0.031 seconds.
>
> 6 tests, 9 assertions, 0 failures, 0 errors
>
> Alex
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
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Norman Timmler

2006-Jan-24 08:17 UTC

head link

[Rails] calculate users age

Am Dienstag, den 24.01.2006, 01:17 -0500 schrieb Paul
Barry:> Weird...
> 
> E:\home\pbarry\projects\rails>ruby -v
> ruby 1.8.2 (2004-12-25) [i386-mswin32]
> 
> E:\home\pbarry\projects\rails>irb
> irb(main):001:0> Date.new(2000,1,1)
> ArgumentError: wrong number of arguments (3 for 0)
>         from (irb):1:in `initialize''
>         from (irb):1:in `new''
>         from (irb):1
> 
On my Ubuntu i have to require ''date'', before i can use it.

irb(main):001:0> Date.new(2006,1,1)
NameError: uninitialized constant Date
        from (irb):1
irb(main):002:0> require ''date''
=> true
irb(main):003:0> Date.new(2006,1,1)
=> #<Date: 4907473/2,0,2299161>
irb(main):004:0>

Maybe this helps.

-- 
Norman Timmler

http://blog.inlet-media.de

Jonas Elfström

2006-Jan-24 08:55 UTC

head link

[Rails] calculate users age

On 1/23/06, SB <richstyles@gmail.com> wrote:> Weird, I was just writing something like this in the course of
> learning ruby.  I doubt you''ll learn anything by just posting a
random
> question and expecting an answer.  You should at least give it a stab.
>
> Hopefully, a more experienced ruby programmer will give me advice to
> improve my code.
>
> Here''s my attempt:
> birthday.rb code
> require "time"
I would not recommend using the class time here since it does not
handle dates before 1970-01-01:
irb> Time.parse("1970-01-01 01:00")
=> Thu Jan 01 01:00:00 W. Europe Standard Time 1970
irb> Time.parse("1969-12-31")
ArgumentError: time out of range
irb> Time.parse("1970-01-01 00:59")
ArgumentError: time out of range

Try the Date in date.rb instead.
http://www.ruby-doc.org/core/files/lib/date_rb.html

Something like this looks like it works:
born=Date.strptime("1969-07-21")
age=Date.today.year-born.year
age=age-1 if Date.today.yday<born.yday

--
Jonas Elfstr?m

2006-Jan-24 09:47 UTC

head link

[Rails] calculate users age

Using ''require "time"'' works fine on my computer
(Mac OSX).  Jan 1,
1970 is the epoch used in the Time class of ruby and might cause
trouble on other operating systems (according to the pickaxe).

However, I agree that using the Date library will probably make my
code more compact and offer more options.

Thanks for pointing this out.

Sam

On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com>
wrote:> On 1/23/06, SB <richstyles@gmail.com> wrote:
> > Weird, I was just writing something like this in the course of
> > learning ruby.  I doubt you''ll learn anything by just posting
a random
> > question and expecting an answer.  You should at least give it a stab.
> >
> > Hopefully, a more experienced ruby programmer will give me advice to
> > improve my code.
> >
> > Here''s my attempt:
> > birthday.rb code
> > require "time"
>
> I would not recommend using the class time here since it does not
> handle dates before 1970-01-01:
> irb> Time.parse("1970-01-01 01:00")
> => Thu Jan 01 01:00:00 W. Europe Standard Time 1970
> irb> Time.parse("1969-12-31")
> ArgumentError: time out of range
> irb> Time.parse("1970-01-01 00:59")
> ArgumentError: time out of range
>
> Try the Date in date.rb instead.
> http://www.ruby-doc.org/core/files/lib/date_rb.html
>
> Something like this looks like it works:
> born=Date.strptime("1969-07-21")
> age=Date.today.year-born.year
> age=age-1 if Date.today.yday<born.yday
>
> --
> Jonas Elfstr?m
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

Alan

2006-Jan-24 10:58 UTC

head link

[Rails] Re: calculate users age

Neatest method I found was posted by Justing in the forum, not so long 
ago :
http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html

def age_at(date, dob)
  day_diff = date.day - dob.day
  month_diff = date.month - dob.month - (day_diff < 0 ? 1 : 0)
  date.year - dob.year - (month_diff < 0 ? 1 : 0)
end

-- 
Posted via http://www.ruby-forum.com/.

Jonas Elfström

2006-Jan-24 12:29 UTC

head link

[Rails] Re: calculate users age

On 1/24/06, Alan <alan@incrediblinc.com> wrote:> Neatest method I found was posted by Justing in the forum, not so long
> ago :
> http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
>
> def age_at(date, dob)
>   day_diff = date.day - dob.day
>   month_diff = date.month - dob.month - (day_diff < 0 ? 1 : 0)
>   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> end
Sorry, could not help myself:

def age_at(date, dob)
  date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
end

And now something for the swedish readers. Check out my validation of
swedish "social security number" in Ruby:
http://plea.se/me/validatePnum.html

--
Jonas Elfstr?m

Paul Barry

2006-Jan-24 15:45 UTC

head link

[Rails] Re: calculate users age

I believe this would techincally not work in leap year, right?

On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com>
wrote:>
> On 1/24/06, Alan <alan@incrediblinc.com> wrote:
> > Neatest method I found was posted by Justing in the forum, not so long
> > ago :
> > http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
> >
> > def age_at(date, dob)
> >   day_diff = date.day - dob.day
> >   month_diff = date.month - dob.month - (day_diff < 0 ? 1 : 0)
> >   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> > end
>
> Sorry, could not help myself:
>
> def age_at(date, dob)
>   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
> end
>
> And now something for the swedish readers. Check out my validation of
> swedish "social security number" in Ruby:
> http://plea.se/me/validatePnum.html
>
> --
> Jonas Elfstr?m
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
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Paul Barry

2006-Jan-24 15:51 UTC

head link

[Rails] calculate users age

So my desktop has the problem as listed in the previous email, but it seems
to work on my laptop fine:

C:\Documents and Settings\PBarry>ruby -v
ruby 1.8.2 (2004-12-25) [i386-mswin32]

C:\Documents and Settings\PBarry>irb
irb(main):001:0> Date.new(2000,1,1)
=> #<Date: 4903089/2,0,2299161>

But on linux, it doesn''t work:

[root@paulbarry ~]# ruby -v
ruby 1.8.4 (2005-12-24) [i386-linux]
[root@paulbarry ~]# irb
irb(main):001:0> Date.new(2000,1,1)
NameError: uninitialized constant Date
        from (irb):1

Any idea what could cause these differences?  3 different environments,
three different results for the same 1 line of code.  Kind of makes me
worried that code I write on one machine will not work on another.

On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:>
> Weird...
>
> E:\home\pbarry\projects\rails>ruby -v
> ruby 1.8.2 (2004-12-25) [i386-mswin32]
>
> E:\home\pbarry\projects\rails>irb
> irb(main):001:0> Date.new(2000,1,1)
> ArgumentError: wrong number of arguments (3 for 0)
>         from (irb):1:in `initialize''
>         from (irb):1:in `new''
>         from (irb):1
>
> On 1/24/06, Alexey Verkhovsky <alex@verk.info> wrote:
> >
> > Paul Barry wrote:
> >
> > > When I copy the text and save it into a file called
BirthdayTest.rb
> > > and then try to run it, I get these errors.  It seems like
Date.new
> > > doesn''t like having 3 arguments.  I am using Ruby 1.8.2
on Win XP.
> > > Any idea why this is?
> >
> > Hmm... worksforme (TM)
> >
> > C:\eclipse\workspace\i2>ruby -v
> > ruby 1.8.2 (2004-12-25) [i386-mswin32]
> >
> > C:\eclipse\workspace\i2>irb
> > irb(main):001:0> Date.new(2000, 1, 1)
> > => #<Date: 4903089/2,0,2299161>
> >
> > C:\>age
> > Loaded suite C:/age
> > Started
> > ......
> > Finished in 0.031 seconds.
> >
> > 6 tests, 9 assertions, 0 failures, 0 errors
> >
> > Alex
> > _______________________________________________
> > Rails mailing list
> > Rails@lists.rubyonrails.org
> > http://lists.rubyonrails.org/mailman/listinfo/rails
> >
>
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Jonas Elfström

2006-Jan-24 16:25 UTC

head link

[Rails] Re: calculate users age

On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:> I believe this would techincally not work in leap year, right?
Why not? yday is 1 to 366 in a leap year.
I tested a few dates in and out of leap years and it seems to work
just fine. If you find a case that breaks the functionality please
tell me. Maybe we should take it offlist...

--
/J
> On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com> wrote:
> >
> > On 1/24/06, Alan <alan@incrediblinc.com > wrote:
> > > Neatest method I found was posted by Justing in the forum, not so
long
> > > ago :
> > >
> http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
> > >
> > > def age_at(date, dob)
> > >   day_diff = date.day - dob.day
> > >   month_diff = date.month - dob.month - (day_diff < 0 ? 1 : 0)
> > >   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> > > end
> >
> > Sorry, could not help myself:
> >
> > def age_at(date, dob)
> >   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
> > end
--
Jonas Elfstr?m

Jonas Elfström

2006-Jan-24 16:34 UTC

head link

[Rails] calculate users age

On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:>  But on linux, it doesn''t work:
>  [root@paulbarry ~]# irb
>  irb(main):001:0> Date.new(2000,1,1)
>  NameError: uninitialized constant Date
>          from (irb):1
>
>  Any idea what could cause these differences?
Somehow the date class is preloaded in some of your installations and
in some not, I leave the story behind that to the wizards. Always do:
require ''date.rb''
and you will be fine in any environment.

--
Jonas Elfstr?m

Rob Biedenharn

2006-Jan-24 18:49 UTC

head link

[Rails] Re: calculate users age

A friend, <http://lathi.net/>Doug 
<http://lathi.net/>Alcorn, had a similar problem and wrote about the
results.
http://blog.lathi.net/articles/2006/01/05/how-old-are-you

Basically, <http://onestepback.org/>Jim Weirich 
posted the code here:  http://rafb.net/paste/results/rL4Dt798.html

Of course, Jim includes a full test suite, too. ;-)

-Rob

At 1/24/2006 11:25 AM, Jonas Elfstr?m wrote:>On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:
> > I believe this would techincally not work in leap year, right?
>
>Why not? yday is 1 to 366 in a leap year.
>I tested a few dates in and out of leap years and it seems to work
>just fine. If you find a case that breaks the functionality please
>tell me. Maybe we should take it offlist...
>
>--
>/J
>
> > On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com> wrote:
> > >
> > > On 1/24/06, Alan <alan@incrediblinc.com > wrote:
> > > > Neatest method I found was posted by Justing in the forum,
not so long
> > > > ago :
> > > >
> > http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
> > > >
> > > > def age_at(date, dob)
> > > >   day_diff = date.day - dob.day
> > > >   month_diff = date.month - dob.month - (day_diff < 0 ? 1
: 0)
> > > >   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> > > > end
> > >
> > > Sorry, could not help myself:
> > >
> > > def age_at(date, dob)
> > >   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
> > > end
>
>--
>Jonas Elfstr?m
>_______________________________________________
>Rails mailing list
>Rails@lists.rubyonrails.org
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Paul Barry

2006-Jan-24 20:36 UTC

head link

[Rails] Re: calculate users age

it doesn''t work because Date.new(2008,3,1).yday is 61, whereas
Date.new(2007,3,1).yday
is 60.  Looks like Alekexy''s age method is correct and the age_at
method
that relies on yday is incorrect:

require ''test/unit''
class BirthdayTest < Test::Unit::TestCase

 def test_age_at_non_leap_year_with_leap_year_dob
   assert_equal 19, age_at(Date.new(2007, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_at_leap_year_with_leap_year_dob
   assert_equal 20, age_at(Date.new(2008, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_at_non_leap_year_with_non_leap_year_dob
   assert_equal 20, age_at(Date.new(2007, 3, 1), Date.new(1987, 3, 1))
 end

 def test_age_at_leap_year_with_non_leap_year_dob
   assert_equal 21, age_at(Date.new(2008, 3, 1), Date.new(1987, 3, 1))
 end

 def test_age_non_leap_year_with_leap_year_dob
   assert_equal 19, age(Date.new(2007, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_leap_year_with_leap_year_dob
   assert_equal 20, age(Date.new(2008, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_non_leap_year_with_non_leap_year_dob
   assert_equal 20, age(Date.new(2007, 3, 1), Date.new(1987, 3, 1))
 end

 def test_age_leap_year_with_non_leap_year_dob
   assert_equal 21, age(Date.new(2008, 3, 1), Date.new(1987, 3, 1))
 end

end

def age_at(date, dob)
  date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
end

def age(now, birthdate)
 had_birthday_passed_this_year = (now.month * 100 + now.day >birthdate.month
* 100 + birthdate.day)
  if had_birthday_passed_this_year
    now.year - birthdate.year
  else
    now.year - birthdate.year - 1
  end
end

On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com>
wrote:>
> On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:
> > I believe this would techincally not work in leap year, right?
>
> Why not? yday is 1 to 366 in a leap year.
> I tested a few dates in and out of leap years and it seems to work
> just fine. If you find a case that breaks the functionality please
> tell me. Maybe we should take it offlist...
>
> --
> /J
>
> > On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com> wrote:
> > >
> > > On 1/24/06, Alan <alan@incrediblinc.com > wrote:
> > > > Neatest method I found was posted by Justing in the forum,
not so
> long
> > > > ago :
> > > >
> > http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
> > > >
> > > > def age_at(date, dob)
> > > >   day_diff = date.day - dob.day
> > > >   month_diff = date.month - dob.month - (day_diff < 0 ? 1
: 0)
> > > >   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> > > > end
> > >
> > > Sorry, could not help myself:
> > >
> > > def age_at(date, dob)
> > >   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
> > > end
>
> --
> Jonas Elfstr?m
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
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Paul Barry

2006-Jan-24 20:44 UTC

head link

[Rails] Re: calculate users age

This shows the errors in age_at better:

require ''test/unit''
class BirthdayTest < Test::Unit::TestCase

 def test_age_at_non_leap_year_with_leap_year_dob
   assert_equal 19, age_at(Date.new(2007, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_at_leap_year_with_non_leap_year_dob
   assert_equal 20, age_at(Date.new(2008, 2, 29), Date.new(1987, 3, 1))
 end

 def test_age_non_leap_year_with_leap_year_dob
   assert_equal 19, age(Date.new(2007, 3, 1), Date.new(1988, 3, 1))
 end

 def test_age_leap_year_with_non_leap_year_dob
   assert_equal 20, age(Date.new(2008, 2, 29), Date.new(1987, 3, 1))
 end

end

def age_at(date, dob)
  date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
end

def age(now, birthdate)
 had_birthday_passed_this_year = (now.month * 100 + now.day >birthdate.month
* 100 + birthdate.day)
  if had_birthday_passed_this_year
    now.year - birthdate.year
  else
    now.year - birthdate.year - 1
  end
end

On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:>
> it doesn''t work because Date.new(2008,3,1).yday is 61, whereas
Date.new(2007,3,1).yday
> is 60.  Looks like Alekexy''s age method is correct and the age_at
method
> that relies on yday is incorrect:
>
> require ''test/unit''
> class BirthdayTest < Test::Unit::TestCase
>
>  def test_age_at_non_leap_year_with_leap_year_dob
>    assert_equal 19, age_at(Date.new(2007, 3, 1), Date.new(1988, 3, 1))
>  end
>
>  def test_age_at_leap_year_with_leap_year_dob
>    assert_equal 20, age_at(Date.new(2008, 3, 1), Date.new(1988, 3, 1))
>  end
>
>  def test_age_at_non_leap_year_with_non_leap_year_dob
>    assert_equal 20, age_at(Date.new(2007, 3, 1), Date.new(1987, 3, 1))
>  end
>
>  def test_age_at_leap_year_with_non_leap_year_dob
>    assert_equal 21, age_at(Date.new(2008, 3, 1), Date.new(1987, 3, 1))
>  end
>
>  def test_age_non_leap_year_with_leap_year_dob
>    assert_equal 19, age( Date.new(2007, 3, 1), Date.new(1988, 3, 1))
>  end
>
>  def test_age_leap_year_with_leap_year_dob
>    assert_equal 20, age(Date.new(2008, 3, 1), Date.new(1988, 3, 1))
>  end
>
>  def test_age_non_leap_year_with_non_leap_year_dob
>    assert_equal 20, age(Date.new(2007, 3, 1), Date.new(1987, 3, 1))
>  end
>
>  def test_age_leap_year_with_non_leap_year_dob
>    assert_equal 21, age(Date.new(2008, 3, 1), Date.new(1987, 3, 1))
>  end
>
> end
>
> def age_at(date, dob)
>   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 : 0 )
> end
>
> def age(now, birthdate)
>  had_birthday_passed_this_year = (now.month * 100 + now.day >>
birthdate.month * 100 + birthdate.day)
>   if had_birthday_passed_this_year
>     now.year - birthdate.year
>   else
>     now.year - birthdate.year - 1
>   end
> end
>
> On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com> wrote:
> >
> > On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:
> > > I believe this would techincally not work in leap year, right?
> >
> > Why not? yday is 1 to 366 in a leap year.
> > I tested a few dates in and out of leap years and it seems to work
> > just fine. If you find a case that breaks the functionality please
> > tell me. Maybe we should take it offlist...
> >
> > --
> > /J
> >
> > > On 1/24/06, Jonas Elfstr?m <jonelf@gmail.com > wrote:
> > > >
> > > > On 1/24/06, Alan <alan@incrediblinc.com > wrote:
> > > > > Neatest method I found was posted by Justing in the
forum, not so
> > long
> > > > > ago :
> > > > >
> > >
http://wrath.rubyonrails.org/pipermail/rails/2005-December/006145.html
> > > > >
> > > > > def age_at(date, dob)
> > > > >   day_diff = date.day - dob.day
> > > > >   month_diff = date.month - dob.month - (day_diff <
0 ? 1 : 0)
> > > > >   date.year - dob.year - (month_diff < 0 ? 1 : 0)
> > > > > end
> > > >
> > > > Sorry, could not help myself:
> > > >
> > > > def age_at(date, dob)
> > > >   date.year - dob.year - ( (date.yday-dob.yday) < 0 ? 1 :
0 )
> > > > end
> >
> > --
> > Jonas Elfstr?m
> > _______________________________________________
> > Rails mailing list
> > Rails@lists.rubyonrails.org
> > http://lists.rubyonrails.org/mailman/listinfo/rails
> >
>
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Jonas Elfström

2006-Jan-25 08:32 UTC

head link

[Rails] Re: calculate users age

On 1/24/06, Paul Barry <mail@paulbarry.com> wrote:> This shows the errors in age_at better:
Thanks for pointing this out! I can''t imagine why I did not think of
this.

I am not in any way an endorser of trying to make code as short as
possible but out of curiosity I fixed my one-line class so that it now
correct but "unreadable":

def age_at(date, dob)
  date.year - dob.year - (date.month-dob.month < 0 ? 1 :
date.day-dob.day < 0 ? 1:0)
end

--
Jonas Elfstr?m

Norman Timmler

2006-Jan-25 15:39 UTC

head link

[Rails] calculate users age

Am Montag, den 23.01.2006, 17:05 +0100 schrieb Norman
Timmler:> I made a small enhancement for the Date class from it:
> 
> class date
>   def age(today = self.class.today)
>     today.year - year - ((today.month * 100 + today.day >= month * 100 +
> day) ? 0 : 1)
>   end
> end
I cleaned it a up a bit and made it more readable:

class Date
  def age(base = self.class.today)
    base.year - year - ((base.month * 100 + base.day >= month * 100 +
day) ? 0 : 1)
  end
end

Use it like that:

# to get the age for today
Date.new(1978,4,20).age

# to get the age for January, the 1st, 2020
Date.new(1978,4,20).age(Date.new(2020,1,1))

You can validate the age of a person in this simple way:

class Person < ActiveRecord::Base
  validates_inclusion_of :age, :in=>18..99

  def age
    # expecting that you have an attribute ''date_of_birth''
    # filled with a Date object
    date_of_birth.age
  end
end
-- 
Norman Timmler

http://blog.inlet-media.de

stiv

2006-Jan-29 01:57 UTC

head link

[Rails] Re: calculate users age

Here is a little bit i just put together.
I''ve not made it pretty and have only done some basic testing.

Context: this function is in a model which has a Date field called dob
it returns the age in "y years m months d days old" format skipping 
values that are empty and pluralizing year month and day as appropriate.

ex: (Time.now = 2006/01/28)
dob               [time_ago_in_words]   [object.age_in_words]
2004-02-21 (age = 707 days)         (1 year 11 months 7 days old)
2002-01-28 (age = 1461 days)       (4 years old)
2005-08-20 (age = 161 days)         (5 months 8 days old)


==========================	def age_in_words
		if dob == nil
		 "--"
		else
		 now = Time.now
		 ydiff = now.year - dob.year
		 mdiff = now.month - dob.month
		 ddiff = now.day - dob.day
		 if ((mdiff < 0) && (ydiff > 0))
		 	y = ydiff - 1
		 	m = mdiff + 12
		 else
		   y = ydiff
		   m = mdiff
		 end
		 if ((ddiff < 0) && (mdiff != 0))
		 	m = m - 1
		 	dim = Time.days_in_month(dob.month+m,dob.year+y)
		 	d = (dim - dob.day) + now.day
		 else
		 	d = ddiff
		 end

		end
		ys = "year"
		ms = "month"
		ds = "day"
		if (y.abs > 1)
			ys= ys.pluralize
		end
		if (m.abs > 1)
			ms = ms.pluralize
		end
		if (d.abs > 1)
			ds = ds.pluralize
		end
		year_string = (y !=  0)?"#{y} #{ys} ":""
		month_string = (m != 0)?"#{m} #{ms} ":""
		day_string = (d != 0)?"#{d} #{ds}":""
		return "#{year_string}#{month_string}#{day_string} old"
	end

-- 
Posted via http://www.ruby-forum.com/.

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