Believe me, thats what I have been doing for the past couple of hours!! JfC : 5 & 6 LJ : 7 and lots of other reading....
It helps newbies to hit the books and read about ranks, cells and frames when trying to decipher the matrix multiplication. A reference to this in the FAQ might help. Thanks! On 10/1/06, Henry Rich <[EMAIL PROTECTED]> wrote:
May I suggest chapters 5 and 6 of _J for C Programmers_ (available in J6 by F1, then JfC) Henry Rich > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > Yuvaraj Athur Raghuvir > Sent: Sunday, October 01, 2006 2:08 PM > To: Programming forum > Subject: Re: [Jprogramming] J FAQ > > I am still struggling with ranks, cells and frames. Thanks > for the pointers. > > > > > On 10/1/06, Miller, Raul D <[EMAIL PROTECTED]> wrote: > > > > Yuvaraj Athur Raghuvir wrote: > > > u . v is defined by u@(v"(1+lv,_)) , ... > > ... > > > Q1. What does the part "1+lv" mean? > > > > It's part of v"(1+lv,_) > > > > This is an expression involving rank. See also > > http://www.jsoftware.com/help/dictionary/intro20.htm > > http://www.jsoftware.com/help/dictionary/d600v.htm > > > > > I assume lv means rank of * which the dictionary states is 0 0 0 . > > > > Actually, lv is the left rank of v, which is the middle element > > of that vector. The three numbers are: monad rank, > > left rank, right rank. > > > > > Q2. There is a third 0 in the rank definition of *. That is being > > ignored. > > > Why? > > > > Because the monad definition of * is not being used here. > > > > > This gives me: > > > > > Q3. But how does J pick the column of B here as the cells > to which to > > apply > > > "*"? Can this be illustrated with appropriate J command > to display the > > > columns of B that would be consumed when * is applied? > > > > Here is an expression which uses that rank with a different verb: > > > > A ;"1 _ B > > > > I hope this helps. > > > > -- > > Raul > > > > > > > ---------------------------------------------------------------------- > > 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
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