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Replacing 1 to many in a list

  • To: mathgroup at
  • Subject: [mg29250] Replacing 1 to many in a list
  • From: Chris Johnson <cjohnson at>
  • Date: Fri, 8 Jun 2001 04:15:35 -0400 (EDT)
  • Sender: owner-wri-mathgroup at

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}

Any suggestions?

Thanks in advance,

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