Re: Cases

*To*: mathgroup at smc.vnet.net*Subject*: [mg50454] Re: [mg50423] Cases*From*: "David Park" <djmp at earthlink.net>*Date*: Sat, 4 Sep 2004 01:43:37 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Jerry, x = {a, b, c, d, d}; Not[d] // FullForm Not[d] I don't see any of those in the list. Cases[x, a_ /; a =!= d] {a, b, c} This method might be easier. Clear[x] {a, 0, b, 0, d} == {x, 0, y, 0, z} // Thread % /. True -> Sequence[] {a == x, True, b == y, True, d == z} {a == x, b == y, d == z} David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: Blimbaum, Jerry AA R22 [mailto:jerry.blimbaum at navy.mil] To: mathgroup at smc.vnet.net Given: x = {a,b,c,d,d}; Applying Cases[x,d] gives an output of {a,b,c}...... However, Cases[x,Not[d]] gives as output an empty list { }... I expected {a,b,c}..... Why didnt I get that? This issue came up when using Thread on vectors...and in some cases the Thread resulted in 0 == 0 so it's output in the list was True....and I wanted to remove them.... thanks.....jerry blimbaum