Finding Hazard Function from Survival Function

[izzah]

Anyone know how to find the hazard function when given the survival function. I am able to calculate the cumulative hazard function, but cannot find a formula for just the hazard function. survival function is:
S(t)=e^(-at-bt2)

 

[NateTG]

http://mathworld.wolfram.com/HazardFunction.html

Seems to indicate you need a probability function as well.

 

[PerennialII]

Or if you don't have them available for, say, a specific distribution, go with numerical approximations.

 

[artbio]

The hazard function is:

$$h(t)=- \frac{d Ln[S(t)]}{dt}$$

The cumulative hazard function is:

$$H(t)=-Ln[S(t)]$$