'J in 5 minutes' is an elevator pitch. There should be no thought of
'covering' hooks, tacit code, arrays, or anything else. You want to
show something glitzy and cool that you can type in 5 minutes. I said
'type' - it might take a week to design, but if you can type it in,
while talking about it, in 5 minutes & get a cool demo, that's a winner.
No matter what you do, J code is going to look like Greek, so the main
thing is to smile as you type and make it clear that the Greek makes
perfect sense to you.
THIS IS NOT TEACHING - it's selling. Focus on the result, not how it
was achieved.
Spreadsheets were cool in 1983, but not now.
Henry Rich
On 2/16/2014 3:18 PM, Pascal Jasmin wrote:
if this spreadsheet type application were a candidate for J in 5 minutes, I
would vote for:
hooks not being covered at all, or the example started with the fork version
(which has no scary expletives), and then perhaps hooks introduced at the end
with the intermediate shortened version of:
(+ 1.05 * ])/\.(10#_1000),10000
----- Original Message -----
From: Bo Jacoby <bojac...@yahoo.dk>
To: "programm...@jsoftware.com" <programm...@jsoftware.com>
Cc:
Sent: Sunday, February 16, 2014 2:21:43 PM
Subject: Re: [Jprogramming] J in 5 minutes
Use a hook to save a little writing
(+1.05&*)/\.(10#_1000),10000
3711.05 4486.72 5225.45 5929 6599.04 7237.18 7844.94 8423.75 8975 9500 10000
Den 20:16 søndag den 16. februar 2014 skrev Raul Miller <rauldmil...@gmail.com>:
Here's another way of seeing those balances at the end of each year. Note
that it follows the right to left pattern of your original setup:
([ + 1.05 * ])/\.(10#_1000),10000
3711.05 4486.72 5225.45 5929 6599.04 7237.18 7844.94 8423.75 8975 9500 10000
And of course, changing the count to 15 (or 16) would get you closer to
your power expression (which is also nice).
Still, I am really fond of /\. (don't forget the dot) for seeing how a
reduction expression proceeds.
Computers are best understood by playing with them, and that's one of J's
greatest strengths (when people are willing to engage it), and one of its
greatest weaknesses (when people are too intimidated to try).
Thanks,
--
Raul
On Sun, Feb 16, 2014 at 1:41 PM, Pascal Jasmin <godspiral2...@yahoo.ca>wrote:
In terms of spreadsheets, J is an excellent replacement, but usually using
the grid is not necessary.
For instance figuring out the loan balance of say a $10k loan at 5%
interest with payment schedule p, where payments are made at end of period
(so interest is calculated on balance right before payment)
p =. 10 $ _1000 NB. first payment is in last position.
([ + 1.05 * ]) / p , 10000
3711.05
([ + 1.0 * ]) / p , 10000
0
If there is any pattern to data, it is usually much more quickly/simply
expressed in J than excel, and if there is no pattern, it is still easily
entered and edited in J as raw data.
an alternate way of getting the above answer
1000 (-~ 1.05 * ])^:10 ] 10000
3711.05
seeing the balance at the end of each year:
1000 (-~ 1.05 * ])^:(i.15) ] 10000
10000 9500 8975 8423.75 7844.94 7237.18 6599.04 5929 5225.45 4486.72
3711.05 2896.61 2041.44 1143.51 200.684
Its pretty easy to see the effect of changes in interest rate or fixed
payment, that in a spreadsheet would alter the number of rows, and get
tedious.
----- Original Message -----
From: Jim Russell <jimsruss...@yahoo.com>
To: "programm...@jsoftware.com" <programm...@jsoftware.com>
Cc:
Sent: Sunday, February 16, 2014 12:54:08 PM
Subject: Re: [Jprogramming] J in 5 minutes
I'm guessing, cause I never got much beyond the labs. I think it presents
an existing array, but lets you receive events for changes to any cell;
given that, what tool for updating one or more cells in an array is better
than J? I think it serves best as a tool to implement a "finished product"
spread sheet for users, rather than one for a non-programmer to build his
own.
I should go back through the grid labs to be sure.
On Feb 16, 2014, at 12:38 PM, Brian Schott <schott.br...@gmail.com>
wrote:
Jim, I did look there. I even looked at the example page. None of the
examples seem to suggest that formulas can be embedded in the cells. Am I
wrong?
---
(B=)
On Feb 16, 2014, at 12:16 PM, Jim Russell <jimsruss...@yahoo.com>
wrote:
See:
http://www.jsoftware.com/jwiki/Grid
Chris did the work using isigraph. I don't know if that has survived
the progress of j6, j7, and j8.
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