It's C because the original question was about C.
On Tue, Jan 29, 2013 at 2:37 AM, Linda Alvord <[email protected]>wrote: > This part I understand: > > btf1=: 3 : ',(i.-n)+/n*i.n=. %:#y' > btf2=: 13 : ',(i.-n)+/n*i.n=. %:#y' > (btf1 -: btf2)"0 *:i.10 > 1 1 1 1 1 1 1 1 1 1 > 5!:4 <'btf1' > -- 3 > -- : -+- ,:',(i.-n)+/n*i.n=. %:#y' > 5!:4 <'btf2' > -- [: > │ -- [: > │ +- , > │ │ -- [: > +----+ ------+- i. > │ │ │ L- - > │ │ │ > --+ L----+- / --- + > │ │ > │ │ -- ] > │ L-----+- * > │ L- i. > │ -- [: > L----+- %: > L- # > > > Roger, I don't understand what you are doing in this next section: > > n=sqrt(m); > q=m-n; > for(i=n-1;i>=0;--i) for(j=i;j<=q;j+=n) *r++=j; > > 1 What is m? > 2 What is for? > 3 Is this C (I don't know C and it isn't J) > > Linda > > > > > -----Original Message----- > From: [email protected] > [mailto:[email protected]] On Behalf Of Roger Hui > Sent: Monday, January 28, 2013 7:10 PM > To: Programming forum > Subject: Re: [Jprogramming] reverse table row indices using indices > > n=sqrt(m); > q=m-n; > for(i=n-1;i>=0;--i) for(j=i;j<=q;j+=n) *r++=j; > > > On Mon, Jan 28, 2013 at 4:06 PM, Roger Hui <[email protected] > >wrote: > > > From that: > > > > btf1=: 3 : ',(i.-n)+/n*i.n=. %:#y' > > (btf -: btf1)"0 *:i.10 > > 1 1 1 1 1 1 1 1 1 1 > > > > A simpler C implementation derives: > > > > n=sqrt(m); > > for(i=n-1;i>=0;--i) for(j=0;j<m;j+=n) *r++=i+j; > > > > > > > > > > On Mon, Jan 28, 2013 at 3:47 PM, Brian Schott > <[email protected]>wrote: > > > >> I think I got it. > >> > >> btf =: monad define NB. Brians transpose flip > >> n=. %:#y > >> r=. i. 0 > >> for_j. i. n do. > >> for_k. i. n do. > >> r =. r, (_2*j)+(n-1)+j+n*k > >> NB. smoutput i1 > >> end. > >> end. > >> r > >> ) > >> > >> btf i. 9 > >> 2 5 8 1 4 7 0 3 6 > >> --------------------------------------------------------------------- > >> - 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
