Hello Erik,

On May 10 11:19 96, Erik Huelsmann of 2:500/19.1929 wrote:

 EH> I am looking for some routine that (helps me or does 
 EH> itself) converts infix-math-expressions to 
 EH> postfix-math-expressions.

a) The Art of Computer Programming. (Knuth). Part1 ? 

(Fundamental Algorithms). Page 336 talsk about preOrder, postOrder
presentation of formulas extracted from the binary tree presentation of the
formula. 

b) you have to parse the expression and build a parse tree and use
postorder traversal methods.

 EH> X*(X'*X)^(-1)*X'*y

 EH> X X ' X * -1 ^ X * y *

to parse such expressions, i would use an LEX/YACC tool. I don't know if
such a tool is available for Pascal. (the lexx/yacc i can write such a
parser/scanner in a few lines of code).

But of course you can implement the parser for yourself. if you don't know
how to write an lexical parser for an LR1 grammatic, i would suggest a book
about compiler construction. 


 WARPED!, Mario

--- Msgedsq/2 2.2e