Editing Mixture model (section)

===Assessing projectile accuracy (a.k.a. circular error probable, CEP)===
Mixture models apply in the problem of directing multiple projectiles at a target (as in air, land, or sea defense applications), where the physical and/or statistical characteristics of the projectiles differ within the multiple projectiles. An example might be shots from multiple munitions types or shots from multiple locations directed at one target. The combination of projectile types may be characterized as a Gaussian mixture model.<ref>Spall, J. C. and Maryak, J. L. (1992). "A feasible Bayesian estimator of quantiles for projectile accuracy from non-i.i.d. data." ''Journal of the American Statistical Association'', vol. 87 (419), pp. 676–681. {{JSTOR|2290205}}</ref> Further, a well-known measure of accuracy for a group of projectiles is the [[circular error probable]] (CEP), which is the number ''R'' such that, on average, half of the group of projectiles falls within the circle of radius ''R'' about the target point. The mixture model can be used to determine (or estimate) the value ''R''. The mixture model properly captures the different types of projectiles.