Tests for Comparing Weighted Histograms. Review and Improvements
  Histograms with weighted entries are used to estimate probability density functions. Computer simulation is the main application of this type of histograms. A review on chi-square tests for comparing weighted histograms is presented in this paper. Improvements to these tests that have a size closer to its nominal value are proposed. Numerical examples are presented for evaluation and demonstration of various applications of the tests. 
Nikolai Gagunashvili
physics.data-an astro-ph.IM hep-ex nucl-ex stat.AP