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+c function ploren.f
+c
+c source
+c   Bevington, page 51.
+c
+c purpose
+c   evaluate lorentzian probability function
+c
+c usage
+c   result = ploren (x, averag, width)
+c
+c description of parameters
+c   x      - value for which probability is to be evaluated
+c   averag - mean of distribution
+c   width  - full width at half maximum of distribution
+c
+c subroutines and function subprograms required
+c   none
+c
+	function ploren (x,averag,width)
+1	ploren=0.1591549431*width/((x-averag)**2+(width/2.)**2)
+	return
+	end