;PURPOSE:
;	This script will calculate the relative flux of cosmic muons from 
;	some angle Theta=ThetaMin to Theta=ThetaMax assuming a cos^2 
;	distribution.  Zenith is at Theta=0 and the horizon is at 
;	Theta=pi/2.

pro muon_cos_sqrd_dis,ThetaMin=ThetaMin,ThetaMax=ThetaMax

If (not keyword_set(ThetaMin)) then ThetaMin = 0
If (not keyword_set(ThetaMax)) then ThetaMax = !pi/2

ThetaMin=float(ThetaMin)
ThetaMax=float(ThetaMax)

A=double(4./(!pi))
RelativeFlux=A*(double((ThetaMax-ThetaMin))/2);-(sin(2*ThetaMax)-sin(2*ThetaMin))/4)

print,RelativeFlux

end