Have you noticed 9!:3 yet? (Or, if you are using anything but the console version, there's also a menu option.)
Good luck, -- Raul On Fri, Nov 18, 2011 at 6:13 PM, Alexander Epifanov <[email protected]>wrote: > Yes, I am ready J for C now. > But, of course, I understand most if the things. > > The main error: I thought that J is like K, but has more features. > The problem I found: J vocabulary has much more verbs. Most of the > verbs in K is one symbol, in J there are a lot of one-two-three symbol > verbs and many special construction. K is much simpler at the point . > Sometimes it is hard for me to understand what is it: 1 2 +/@:* 3 4 or > 1 2 (+/ @"*) 3 4 or 1 2 (+/@ "*) 3 4. But 5!:2 should help. > > For example I would write the following example in K: > *>|/ > and for me it looks easier at the moment. Will try to overwrite it J. > > Regards, > > On Fri, Nov 18, 2011 at 11:40 PM, Kip Murray <[email protected]> wrote: > > By all means, post questions here. > > > > And I think you will like J for C programmers (click on JfC at top of > > vocabulary page), here is a sample from Chapter 2 Culture Shock: > > > > Here's an example. Figure out what the following code does: > > > > int i, j, maxcol = 0; > > float maxval = x[0][0]; > > for(i = 0;i<=xsize0;++i) { > > for(j = 0;j<=xsize1;++j) { > > if(x[i][j] > maxval) { > > maxval = x[i][j]; > > maxcol = j; > > } > > } > > } > > > > Not too hard. When the code finishes, maxval is the largest element in > > the array x, and maxcol is the column number it was in. As it happens, > > all I wanted was the column number, but there was no way for you to know > > that. > > > > The same code in J: > > > > maxcol =. (i. >./) >./ x > > > > With some practice, you will learn to read this code just as easily as > > you read the C. You will recognize the / as an indicator of a loop that > > accumulates a result, and the i. as an indicator of a search. The =. > > and =: tokens indicate assignment. > > > > What happened to the if statement? > > > > It's built into the >. primitive. Just as most loops are hidden inside > > primitives, so are most conditionals. The functions you write can also > > contain built-in conditionals. > > > > What's the statement delimiter? > > > > There isn't one. Statements are exactly one line long. > > > > I've looked at some J code. Every other character is a period or a > > colon. I've got spots before my eyes. How can anybody read this stuff? > > > > . . . > > > > > > On 11/18/2011 3:45 PM, Raul Miller wrote: > >> If you cannot find the right reference material, then just post > questions > >> here. > >> > >> We have a "J for C Programmers" book, but we do not have a "J for K > >> Programmers". And in some ways, J is more complicated to use than K. > (K > >> tends to be simpler for 1 dimensional data and for tree structures.) > >> > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > -- > Regards, > Alexander. > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
