I got it working and found out "#" does the same thing, I have all I need except how to plot multiple line segments (using plot) on the same graph. In other words, how ro plot a vector field on a plane. Thanks again.
From: mijj <[email protected]> To: Programming forum <[email protected]> Sent: Monday, August 8, 2011 12:22 AM Subject: Re: [Jprogramming] value error hi Mr Kane.. from a novice perspective (having come from those pitfalls only recently) i notice (as well as the assignment lapse, which i continjue to do all the time) 2 errors in the use of :[ return ]: i.e... :[ return t ]: should actually be :[ t return. ]: for it to work as i'm guessing you expect (returning the value "t"?). First problem... missing :[ . ]: from the end of "return". Second... :[ return. t ]: wouldn't return the value "t" after it. It would quit immediately returning the most recent expressed value *before* the return. So, if you want to return the value "t" ... :[ t return. ]: ........ (nb.^:1) i like to use :[ return. ]: as an explicit marker to help with cursory examination of a construction. I don't know if a superfluous :[ return. ]: has a performance penalty, but until i create something where it makes a difference, i find it useful. (nb.^:2) i'm toying with using :[ ... ]: in emails to isolate bits of J within text to make it stand out. I've not decided yet if it looks too silly to continue using.) On 2011-08-08 03:56, nykkyo Kane wrote: > Following is a creenshot of my "J" console. I do not understand why I am > getting a error> > ================= > compress 4 : 0 > i =. 0 > t =. 0$0 > while. i< $x do. > if. 1 = i{x do. t =. t , i{y end. > i =.>:i > end. > return t > ) > > compress 4 : 0 > i =. 0 > t =. 0$0 > while. i< $x do. > if. 1 = i{x do. t =. t , i{y end. > i =.>:i > end. > return t > ) > b compress a > |value error: compress > | b compress a > a > 11 12 13 14 15 16 17 18 19 20 > b > 1 0 1 0 1 0 1 0 1 0 > ---------------------------------------------------------------------- > 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
