how to read y axis in kernel density graph [duplicate]

• The linked CV question from Huber should address your technical knowledge gap here. The literal interpretation of the Y-axis is a dimensionless quantity, like an infinitesimal grain of probability sand. An interpretation of a smoothed density estimate that's appropriate for applied audiences and scholarly journals is to calculate estimated "probability area" in pre-specified ranges. If the X-axis here were times to recurrence of cancer in months following therapy, you might be interested in risk of 1 year recurrence which you could estimate by using the function integrate(...). – AdamO Apr 9 '13 at 21:26