Tell me more ×
Cross Validated is a question and answer site for statisticians, data analysts, data miners and data visualization experts. It's 100% free, no registration required.

This may be a naive question, but here goes. If I have a set of empirical data and fit a kernel density to it, and then obtain a new single value which possibly comes from the same process which generated the original data set, can I assign a probability that this new value belongs to the set/process by simply reading the value off the y axis where the new value on the x axis intersects the kernel density line and dividing by the area under the density line?

share|improve this question

1 Answer

up vote 10 down vote accepted

No, I'm afraid not. The kernel density estimand is the probability density function. The y-value is an estimate of the probability density at that value of x, so the area under the curve between x1 and x2 estimates the probability of the random variable X  falling between x1 and x2, assuming that X was generated by the same process that generated the data which you fed into the kernel density estimate. The kernel density estimate doesn't say anything about the probability a new value was generated by the same process.

share|improve this answer
if the yaxis is c(0, 0.05, 0.10, 0.15) and xaxis c(5,10,15,20) and mean being 12.5. Would you explain this charts as there is 15% chance that mean would be 12.5? I am having a difficult time understanding the y-axis? – user1471980 Nov 9 '12 at 15:18

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.