Probability density function is a statistical expression defining the likelihood of a series of outcomes for a continuous variable, such as a stock or ETF return.

Beronika Daxner, Antoine Genitrini, Bernhard Gittenberger, Cécile Mailler, THE RELATION BETWEEN TREE SIZE COMPLEXITY AND PROBABILITY FOR BOOLEAN FUNCTIONS GENERATED BY UNIFORM RANDOM TREES, Applicable ...

D. O. Loftsgaarden, C. P. Quesenberry, A Nonparametric Estimate of a Multivariate Density Function, The Annals of Mathematical Statistics, Vol. 36, No. 3 (Jun., 1965 ...