Re: natural log of a summation

In article <25295402.1112312867776.JavaMail.jakarta@xxxxxxxxxxxxxxxxxxxxxx>,
Adam Hartshorne <adam@xxxxxxxxxxxxxxxxx> wrote:

>Ok I am currently implementing something and have encountered the
>following problem.

>I have to code "the natural log of "the product" of "the sum" of a
>function. Ok for progamming reasons which are hard to explain, I changed
>this to

>i.e. ln(TT E f(x)) (bear with the symbols!)

>"The sum of" the "natural log" of "the sum" of a function.

>i.e. E ln E f(x)

>Ok thats all straight forward enough to program, however my problem
>comes because I am dealing with vectors, and the result of the "the sum"
>of a function is a vector itself. And of course this vector may contain
>+ve or -ve x,y, and z components.

>I have currently implemented taking the natural log of each component,
>but obvious this hits problems when a component is -ve.

>Any suggestions? Should I be taking the natural log of each component anyway?

Without a bit more context, it's hard to say what is going on here.
Who is asking you to program this? Why don't you ask that person what
he or she means by the log of a vector, and what you are supposed to
do about negative numbers?

Robert Israel israel@xxxxxxxxxxx
Department of Mathematics http://www.math.ubc.ca/~israel
University of British Columbia Vancouver, BC, Canada

.

Relevant Pages

  • Re: no prime number in the given range
    ... [Phil Carmody] ... MW's correct - they've got a double sum. ... The man who is always worrying about whether or not his soul would be ...
    (sci.math)
  • Re: Series problem
    ... Taylor series expansions with their sum functions for tomorrow. ... "ln is the natural log." ...
    (comp.sys.hp48)