NB. example, avoiding (%) and (%:)
L=.1 NB. length of pendulum
g=.9.8 NB. gravitation
(2p1,L,g)*/ .^1,(2^-1),(-2^-1) NB. cycle time
2.00709
Thanks! Bo.
Den lørdag den 3. november 2018 19.23.03 CET skrev Roger Hui
<[email protected]>:
> And, J [in isolation] often doesn't solve anything interesting.
The following could be considered interesting for suitable definitions of
interesting:
http://code.jsoftware.com/wiki/Essays/Kakuro
http://code.jsoftware.com/wiki/Essays/KenKen
http://code.jsoftware.com/wiki/Essays/Krypto
http://code.jsoftware.com/wiki/Essays/moo
http://code.jsoftware.com/wiki/Essays/Nurikabe
http://code.jsoftware.com/wiki/Essays/Set_Game
http://code.jsoftware.com/wiki/Essays/Sudoku
On Sat, Nov 3, 2018 at 11:01 AM Raul Miller <[email protected]> wrote:
> "J is too rich for beginners" is not really the case, in my experience.
>
> Preschoolers can pick up a bit of J without problem. They'll get bored
> easily, but that whole motivation side of education hits you on every
> topic.
>
> The problem is more that most of us don't have anything useful to teach.
>
> And, J [in isolation] often doesn't solve anything interesting. It's
> only when you combine it with other topics that it can become useful.
>
> Thanks,
>
> --
> Raul
>
> On Sat, Nov 3, 2018 at 5:31 AM 'Bo Jacoby' via Chat <[email protected]>
> wrote:
> >
> > Regarding matematical notation.
> > J is too rich for beginners.
> > We first learn addition, subtraction, multiplication and division. Later
> we use the minus sign for negative numbers, like -2. Then we do not need
> subtraction any more. The difference is written 7+-2, This was not taught
> in school.
> > Calculations are easier when avoiding subtraction:
> > (a+-b)^2 = (a+-b)(a+-b) = aa+a-b+-ba+-b-b = a^2+b^2-2ab.
> > Note that a-b is now the product (a)(-)(b) = -ab. You should normally
> write -ab rather than a-b in order not to confuse your reader. The
> difference is written a+-b.
> > Of course (-)=-1, or simply -=-1.
> > Then we learned about exponentiation. a^b.
> > The power a^- is the reciprocal to a. Formulas need no more contain
> fraction bars. We may forget about division.
> > The power 2^- is one half, and a^2^- is the square root. Formulas
> need no more contain root signs.
> > Multiplication signs are usually omitted, but 23 means twenty three
> rather than two times three. Write the product 2^1 3^1 to avoid
> confusion. Then the multiplication sign is no longer needed.
> > These simplifications make elementary formulas nicer.
> > In J you need not use the division and reciprocal sign (%), the square
> root sign (%:), the subtraction (-),
> > /Bo
> >
> >
> >
> >
> >
> > Den lørdag den 3. november 2018 08.02.42 CET skrev 'robert
> therriault' via Chat <[email protected]>:
> >
> > Mark Guzdial, a computer education researcher mentioned the Computer
> and Mathematical Notation paper http://www.jsoftware.com/papers/camn.htm
> in his blog
> https://computinged.wordpress.com/2018/11/02/fixing-mathematical-notation-with-computing-and-proving-it-with-education/
> >
> > Further he cited it as an example where success in changing mathematical
> notation is measured by using the notation as a better way to educate
> students and notes the books that Ken wrote using J to teach mathematics. I
> have been surprised that more have not picked up this very important aspect
> of J.
> >
> > Neat to see this turn up in the educational component of computer
> science.
> >
> > Cheers, bob
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
