Added analytical distance expression
Added analytical distance expression

sheim/drake,billhoffman/drake,billhoffman/drake,billhoffman/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,sheim/drake