-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Omar Lakkis
Sent: Wednesday, May 25, 2005 10:08 AM
To: r-help at stat.math.ethz.ch
Subject: Re: [R] precision problem
all.equal is helpful when I am comparing equality of two matrices.
However, when I am comparing two individual number with > or
< is my best bet doing if( abs(x - y) < tolerence) or is
there a function like all.equal that has the same default tolerence?
On 5/25/05, Omar Lakkis <uofiowa at gmail.com> wrote:
Thank you all.
all.equal is very helpful since I am also interested in finding the
mismatched prices.
On 5/25/05, John Fox <jfox at mcmaster.ca> wrote:
Dear Omar,
Perhaps I'm missing something, but why not just subtract
from the other and test the difference in relation to the
that you require for the comparison? E.g., to test near equality,
something like, abs(A - B) < 1e-13.
I hope this helps,
John
--------------------------------
John Fox
Department of Sociology
McMaster University
Hamilton, Ontario
Canada L8S 4M4
905-525-9140x23604
http://socserv.mcmaster.ca/jfox
--------------------------------
-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of
Sent: Wednesday, May 25, 2005 9:09 AM
To: r-help at stat.math.ethz.ch
Subject: [R] precision problem
I have prices that I am finding difficult to compare with ==,
and >, due to precision. For example: the numbers should
match, with '==', but they differ in the magnitude of
bunch of calculations that I run on them. Programming
am used to implementing a function that compares the difference
between the numbers to a pre determined precision factor. This
could be very slow when I have two matrices of numbers that I
could otherwise compare with a simple '==', '>' or '<' in R.
What is teh best solution for this problem?
Can I control the precision of ==, > and < without having to
reimplement the operations in a slow way?