Re: Elegant syntax for multiple conditional assignment?
- To: mathgroup at smc.vnet.net
- Subject: [mg54410] Re: [mg54337] Elegant syntax for multiple conditional assignment?
- From: Scott Hemphill <hemphill at hemphills.net>
- Date: Sun, 20 Feb 2005 00:08:22 -0500 (EST)
- Reply-to: hemphill at alumni.caltech.edu
- Sender: owner-wri-mathgroup at wolfram.com
On Sat, 19 Feb 2005, Bob Hanlon wrote:
> old={a1,c1,x1,y1};
>
> new={a2,c2,x2,y2};
>
> cond={True,False,True,False};
>
> {a,c,x,y} = If[#[[1]],#[[2]],#[[3]]]&/@
> Transpose[{cond,new,old}]
>
> {a2,c1,x2,y1}
>
> {a,c,x,y} = If[#[[1]],#[[2]],#[[3]]]&/@
> Thread[{cond,new,old}]
>
> {a2,c1,x2,y1}
This isn't what I want. What I want is this:
a1={1,2,3,4,5};
c1={6,7,8,9,10};
x1={11,12,13,14,15};
y1={16,17,18,19,20};
old={a1,c1,x1,y1};
a2={21,22,23,24,25};
c2={26,27,28,29,30};
x2={31,32,33,34,35};
y2={36,37,38,39,40};
new={a2,c2,x2,y2};
cond={True,False,True,False,True} (* Note: five elements *)
What I want is code which takes old, new, and cond and makes this
assignment:
a={21,2,23,4,25};
c={26,7,28,9,30};
x={31,12,33,14,35};
y={36,17,38,19,40};
Scott
--
Scott Hemphill hemphill at alumni.caltech.edu
"This isn't flying. This is falling, with style." -- Buzz Lightyear