MathGroup Archive 2004

[Date Index] [Thread Index] [Author Index]

Search the Archive

How to substitute?

  • To: mathgroup at
  • Subject: [mg45474] How to substitute?
  • From: Steve Gray <stevebg at>
  • Date: Fri, 9 Jan 2004 05:20:43 -0500 (EST)
  • Sender: owner-wri-mathgroup at

\!\(\((y\_0 - z\_3)\)\ \((\(-y\_1\) + z\_3)\)\ \((\(-y\_2\) + 
        z\_3)\)\ \((\(-y\_3\) + z\_3)\)\)

	I have output cells containing various expressions such as 
(y[0]-z[1]) (y[1]-z[2]) (y[4] - z[0]), where I use [x] here to mean
subscript. The integers can have any small values. For compactness of
expression, I want to make substitutions which make the above
expression look like Q[0,1]Q[1,2]Q[4,0]. There are many combinations
of subscript pairs and I don't want to write explicit substitution
rules for every possible combination. I tried doing /.(y[i]-z[j]) ->
Q[i,j] , and /.(y[i_]-z[j_]) -> Q[i,j] but they don't work. 
	Any suggestions will be gratefully received.

  • Prev by Date: Context of option symbols
  • Next by Date: Re: convert notebook into batch file
  • Previous by thread: Re: finding eigenvalues
  • Next by thread: Re: How to substitute?