Re: [R] Greater than 1 or less than 1?

2004-06-20 Thread Ray Brownrigg
> Date: Sun, 20 Jun 2004 18:32:46 -0400 > From: "Zhen Chen" <[EMAIL PROTECTED]> > > I have problem evaluating the expression h = exp(x)/(exp(exp(x))-1) for > large negative x. This expression is actually the probability > that y = 1 when y is a Poisson random variable truncated at 0, hence > mus

Re: [R] Greater than 1 or less than 1?

2004-06-20 Thread Thomas Lumley
On Sun, 20 Jun 2004, Zhen Chen wrote: > I have problem evaluating the expression h = exp(x)/(exp(exp(x))-1) for > large negative x. This expression is actually the probability > that y = 1 when y is a Poisson random variable truncated at 0, hence > must satisfy 0 <= h <= 1. However, when You wou

Re: [R] Greater than 1 or less than 1?

2004-06-20 Thread Peter Dalgaard
"Zhen Chen" <[EMAIL PROTECTED]> writes: > I have problem evaluating the expression h = exp(x)/(exp(exp(x))-1) > for large negative x. This expression is actually the probability > that y = 1 when y is a Poisson random variable truncated at 0, hence > must satisfy 0 <= h <= 1. However, when > x < -

[R] Greater than 1 or less than 1?

2004-06-20 Thread Zhen Chen
I have problem evaluating the expression h = exp(x)/(exp(exp(x))-1) for large negative x. This expression is actually the probability that y = 1 when y is a Poisson random variable truncated at 0, hence must satisfy 0 <= h <= 1. However, when x < -18, I may get an h value that is larger than 1 w