Fortunately, the use of "leap" is valid as long as one doesn't go back
past 1901 or ahead past 2099.
1900 and 2100 aren't leap years (Fine tuning of the leap year calculation ).
Don Kelly
On 20/09/2014 10:53 PM, robert therriault wrote:
Hi Linda,
I share your dream and sometimes the statement 'I have a dream' can change the
world. :-)
On to the weekend puzzle...
The first thing I need to figure out is whether the birthday has happened this
year or not. If it has then I can pretty easily get the number of days since
the birthday using todayno, but if it hasn't then I need to find the number of
days since the previous year's birthday.
'yg mg dg' =: gbday =: 2002 2 2 NB. Groundhog's birthday
'ya ma da'=:afterbday =: 2014 9 20 NB. An example of date after the
birthday
'yb mb db'=:beforebday =: 2014 1 31 NB. An example of a date before the
birthday
bdYet=:(0>-/) &: todayno NB. returns 1 if the current date is in the same
calendar year before the birthday
ya
2014
ya=. ya- afterbday bdYet ({. afterbday),}.gbday NB.use the current year
from example and the birthday
ya
2014
yb
2014
yb=. yb- beforebday bdYet ({. beforebday),}.gbday
yb
2013
Next thing would be to define a vector that gives the accumulated days in the
year if the year were to start on February 1st. The leap year issue means that
the first item in the list will be 29 if it is a leap year. since I have
already figured out whether I am counting from the previous year, I will use
the adjusted year to decide if the year that I am counting from was a leap
year. I will just use a simple (and incorrect) version of leap year.
leap=: 0= 4&|
feb=: 28 + leap ya
feb
28
[daysFebFirst=: +/\ (feb), 31 30 31 30 31 31 30 31 30 31 31
28 59 89 120 150 181 212 242 273 303 334 365
Finally, I create the results.
[yr=:ya-yg NB. number of years
12
[elapsed=: -/ todayno"_1 afterbday,: ya,}.gbday NB. days since the birthday
230
[mr=: +/ elapsed > daysFebFirst NB. number of months
7
[dr=: (<:mr){ elapsed - daysFebFirst
18
yr,mr,dr
12 7 18
And for the case of a date before the birthday Jan 31st 2014 we get
[feb=: 28 + leap yb NB. No change since 2013 is not a leap year
28
[yr=:yb-yg NB. number of years
11
[elapsed=: -/ todayno"_1 beforebday ,: yb ,}.gbday NB. days since the
previous birthday
363
[mr=: +/ elapsed > daysFebFirst NB. number of months
11
[dr=: (<:mr){ elapsed - daysFebFirst
29
yr,mr,dr
11 11 29
Cheers, bob
On Sep 20, 2014, at 10:58 AM, Linda Alvord <[email protected]> wrote:
The J forum is my elementary school set of sub imjects. What you suggest is
exactly what I would hope would happen in a J classroom. All would have J.
All could experiment and exchange ideas. Hopefully they would have solutions
they believe were correct. Then they could explain their thinking to the
entire class and the teacher. At this point in the process, the teacher
would not be a leader but a follower.
Possibly I am dreaming....
Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of robert
therriault
Sent: Saturday, September 20, 2014 1:20 PM
To: [email protected]
Subject: Re: [Jprogramming] Weekend Puzzle - Age of Groundhog born 2002 2 2
Hi Linda,
If you are looking for a way to get learners to be interested in the
problem, why not use the very model of learning that we are using here?
You put a problem out to your class (forum) and see how the responses go.
You as the teacher (moderator) are free to choose the rules, knowing that
the students (participants) are able to put their attention elsewhere if
things are not kept interesting. It is a style of learning that we use on
these forums everyday and it seems to work for us.
What might not work as well is going into the class and showing them how to
solve the problem, as this takes away so much from the experience that we
enjoy when we are learning. The challenge for the teacher is not so much
coming up with a solution, as it is to make sure that they are engaging as
many students as possible. This is especially true at the extremes of the
class' abilities - both the really adept and those that are struggling with
the concepts are where teachers are most valuable.
Just my two bits, but I would probably just start with the question of 'how
would you measure time in metric?' and use that as a way to explore all the
ways that you would count and group the types of time and how they way we
measure time can be pretty crazy and why it might be good if we could get
computers to do the work of taking care of the crazy systems that we have
set up. Where the class would take this in terms of topic is wide open, as a
teacher you just make sure that as the core concepts arise they are covered
accurately.
Cheers, bob
ps. The quickest way to get me to care about the age of your groundhog is to
have one of my classmates start trying to figure it out, but my learning is
usually socially motivated. :-)
On Sep 20, 2014, at 9:35 AM, Joe Bogner <[email protected]> wrote:
Hi Linda
The solution is quite simple and uses one built verb from an addon. I
posted it with the solution masked so others can try it on their own
without accidentally seeing mine
The actual solution is the result of this:
|. solution2
On Sep 20, 2014 11:54 AM, "Linda Alvord" <[email protected]> wrote:
We are talking children here.
Onyadot. emiTetaDot, ffiDst, onyadot, emiTetaDot, emitetad, sepyt and
eriuqer are all denied!
How about using +, -, *, ?, %: and that sort of thing.
I must admit you did get the right answer!
You can also get a second chance.
Cheers, Linda
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Joe
Bogner
Sent: Saturday, September 20, 2014 9:10 AM
To: [email protected]
Subject: Re: [Jprogramming] Weekend Puzzle - Age of Groundhog born 2002 2
2
solution...
1
2
3
4
5
lightly obfuscated for someone who doesn't want the solution
solution1=: 0 : 0
)2 2 2002 onyadot emiTetaDot( ffiDst )02 9 4102 onyadot emiTetaDot(
'emitetad/sepyt' eriuqer
)
to run:
0!:1 |. solution1
solution2 =: 0 : 0
)2 2 2002( ffiDst )02 9 4102(
'emitetad/sepyt' eriuqer
)
0!:1 |. solution2
note: both take advantage of a addon. solution1 uses todayno just because
it was stated in the problem but solution2 is what I'd really use
On Sat, Sep 20, 2014 at 4:54 AM, Linda Alvord <[email protected]>
wrote:
Using the verb todayno which provides the number of days since the
beginning of 1800, write what you need to find the age today of a
groundhog
born on 2002 2 2.
todayno 2014 9 2014
80418
2014 9 20 age 2002 2 2
12 7 18
His age is 12 years, 7 months and 18 days. Use simple J. Check that
your
solution provides a correct answer for you birthday.
Have a pleasant weekend.
Linda
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