Hello,
I am trying to generate random survival times by inverting the function,  S(t)= exp(b*F(t)), where b is constant and F(t) is some cumulative distribution function, let say that F(t) is cdf of normal distribution or any others distributions.
 
as we know that S(t) has uniform distribution on  (0,1) so we can write that
U= exp(b*F(t)), where U is uniform (0,1). Now to generat the time t, we do 
log(U)= b* F(t)
(log(U))/ b = F(t) and then  t = F((log(U))/b)^(-1).
 
My Question  is how we can get the inverse function for the cumulative distribution F(t) in R?. Is there any package in R can help to invert some function especially if this function is pdf or cdf?.
 
Thanks in advance.
	[[alternative HTML version deleted]]

