Re: Replacing 1 to many in a list
- To: mathgroup at smc.vnet.net
- Subject: [mg29265] Re: [mg29250] Replacing 1 to many in a list
- From: BobHanlon at aol.com
- Date: Sat, 9 Jun 2001 03:08:52 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 2001/6/8 4:38:39 AM, cjohnson at shell.faradic.net writes:
>I think this is probably simple, but I can't find a natural way to do it
>yet. I hope someone out there can help. I have a vector numbers with
>some Null's scattered throughout. The number and location of missing data
>varies. For example,
>
>vector = {6, 6, 5, 4, 4, 4, Null, 6, Null, 44, Null, 4, 4, 5}
>
>Position[vector, Null]
>
>{{7}, {9}, {11}}
>
>Now "/." will let me replace all instances of Null with the same variable
>but I want to replace each instance with a different variable. I would
>prefer to use x[1], x[2] and x[3], but if it were easier, then x[7], x[9]
>and x[11] would be OK also.
>
>The prefered end result would be:
>
>{6, 6, 5, 4, 4, 4, x[1], 6, x[2], 44, x[3], 4, 4, 5}
>
{6, 6, 5, 4, 4, 4, Null, 6, Null, 44, Null, 4, 4, 5} /.
(n=1; Null :> x[n++])
{6, 6, 5, 4, 4, 4, x[1], 6, x[2], 44,
x[3], 4, 4, 5}
Bob Hanlon
Chantilly, VA USA