5(+*-)3 is (5+3)*(5-3). If f is a cap ([:) the capped branch simplifies the forks to g h y and g x h y
x=5 y=3 f=+ g=* h=- x (f g h)y is (x f y)g (x h y) x=5 y=3 f=[: g=* h=- x (fgh)y is g (x h y) * (3 - 5) 2008/9/18 Alex Rufon <[EMAIL PROTECTED]> > Hi Ric, > > I have to admit that I'm new to this type of programming with J so > please be patient with my questions. > 1. I initially tried doing a tacit definition of > cmp0=: I. 0 = > |syntax error > | cmp0=: I.0= > So why does the following script not fail anymore (although it doesn't > work)? > cmp0=: I. 0 =, > > 2. M is 2 dimension matrix. The result of ([: I. 0 = ,@]) is 6 and 8. > The code proceeded to amend the data as if it was a vector!!! If I try > to do that manually, I'll get errors. Why? I've always thought that in a > 2 dimension matrix, I need to provide the row and column position for > amends > _ 6} M > |domain error > | _&6}M > _ (6}) M > |length error > | _ 6}M > _& (6}) M > |index error > | _ (6})M > _ 6} M > |index error > | _&(6})M > _ (6)} M > |length error > | _ 6}M > _ (6)} M > |index error > | _ (6)}M > > 3. This is the first time I use [: symbol. I looked it up in the help > file and my brains threw a breaker after reading this : > "For example, 5(+*-)3 is (5+3)*(5-3). If f is a cap ([:) the capped > branch simplifies the forks to g h y and g x h y . The train N g h (a > noun followed by two verbs) is equivalent to N"_ g h . The ranks of the > hook and fork are infinite." > I would appreciate it if somebody can provide a better explanation ... > please. :) > > Thanks. > > r/Alex > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Sherlock, Ric > Sent: Thursday, September 18, 2008 5:20 PM > To: Programming forum > Subject: [Jprogramming] RE: Applying Amend on each row > > ---Alex Rufon wrote: > > What I want to do is to replace all zero in the matrix with infinity. > > ]M=: 4 [EMAIL PROTECTED] > 6 5 9 2 > 4 9 0 7 > 0 4 6 8 > 3 8 1 2 > > amendZeros=: _&(([: I. 0 = ,@])}) > > amendZeros M > 6 5 9 2 > 4 9 _ 7 > _ 4 6 8 > 3 8 1 2 > > Check out Chapter 6.3.3 Linear Indices in Learning J > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Björn Helgason, Verkfræðingur Fugl&Fiskur ehf, Þerneyjarsundi 23, Hraunborgum Po Box 127,801 Selfoss , t-póst: [EMAIL PROTECTED] gsm: +3546985532 Landslags og skrúðgarðagerð, gröfuþjónusta http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) `. )----' (")_(")
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