*file member=acf_fnip library=snoman language=fortran77 date=21:Mar:2002
     
 <<<      subroutine acf_FnIP(ihist,finprod)
     
    *     ACF: Calculate inner product of the event angular correlation function
    *          -- with the function for an ideal ring of 8 degrees width centered
    *             at 42 deg from the Cerenkov cone's central axis.
    *          -- with the difference between CC and NC average correl fns.
     
    *     Contact:  W. Heintzelman, Penn
    *     Verified: 
    *     Refereed: 
     
    *     Parameters:-
    *     ==========
    *       ihist     in    number of the histogram containing the event correlation
    *                       function in nBinc bins.
    *       finprod  out    inner product of event correlation fn with
    *                       two given functions
     
    *     Common Block Access:-
    *     ===================
    *       none
     
    *     Specification:-
    *     =============
     
    *     Program Notes:-
    *     =============
     
    *     Revision History:-
    *     ================
    *     4.02    W. Heintzelman   First version
    *             N. West          Convert " -> '.
     
            IMPLICIT NONE
     
            include 'acf_evalconst.inc'
     
    *     Argument Declarations:-
    *     =====================
            integer ihist,i
            real finprod(2)
     
    *ENDHEADER
     
    *     Local Variable Declarations:-
    *     ===========================
            real fcorfn(nBinc,2),evtcorfn(nBinc),f
            real vdot                               ! External function
     
            SAVE
     
    *       Definition of the correlation functions for comparison--
            data fcorfn/
         +       0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0000000, 0.0000000
         +     , 0.0000000, 0.0000000, 0.0000000, 0.0013616, 0.0106312
         +     , 0.0307568, 0.0483842, 0.0705887, 0.1016616, 0.1294156
         +     , 0.1533768, 0.1717153, 0.1751436, 0.1702140, 0.1634061
         +     , 0.1551334, 0.1403507, 0.1254586, 0.1160613, 0.1092961
         +     , 0.1056368, 0.1019108, 0.0981908, 0.0959904, 0.0923798
         +     , 0.0927749, 0.0905928, 0.0895655, 0.0872983, 0.0887510
         +     , 0.0883012, 0.0843806, 0.0872679, 0.0866661, 0.0872679
         +     , 0.0878271, 0.0885747, 0.0879426, 0.0902220, 0.0912614
         +     , 0.0925135, 0.0945863, 0.0969629, 0.0991816, 0.1022269
         +     , 0.1059894, 0.1109129, 0.1162011, 0.1231792, 0.1331903
         +     , 0.1452803, 0.1631144, 0.1924184, 0.2516222, 0.5553061
         +     ,-0.122500,-0.122031,-0.120882,-0.120139,-0.121055
         +     ,-0.119626,-0.119322,-0.118398,-0.118366,-0.117244
         +     ,-0.116797,-0.115591,-0.114148,-0.114613,-0.113019
         +     ,-0.111332,-0.110643,-0.109124,-0.108913,-0.107103
         +     ,-0.106118,-0.104784,-0.102913,-0.101098,-0.098688
         +     ,-0.097830,-0.095762,-0.094431,-0.090884,-0.089227
         +     ,-0.086366,-0.084773,-0.082315,-0.079067,-0.076315
         +     ,-0.072448,-0.069868,-0.066265,-0.062686,-0.058537
         +     ,-0.055502,-0.050180,-0.044393,-0.040827,-0.034421
         +     ,-0.029335,-0.022776,-0.016533,-0.009481,-0.001568
         +     , 0.006747, 0.015773, 0.026080, 0.035992, 0.048041
         +     , 0.059550, 0.068791, 0.074761, 0.076930, 0.075507
         +     , 0.074230, 0.070878, 0.069400, 0.066703, 0.064244
         +     , 0.061248, 0.061197, 0.059185, 0.058925, 0.058984
         +     , 0.057317, 0.056719, 0.057352, 0.057081, 0.057347
         +     , 0.058053, 0.057584, 0.058634, 0.060255, 0.062088
         +     , 0.062180, 0.063227, 0.067218, 0.072635, 0.073863
         +     , 0.077428, 0.081303, 0.086558, 0.091959, 0.099373
         +     , 0.105955, 0.116296, 0.124065, 0.136893, 0.152534
         +     , 0.171066, 0.192238, 0.222110, 0.266796, 0.360185 /
     
     
            ! Retrieve event pair angle distn from histogram:
            call HUnpak(ihist,evtcorfn,' ',0)
     
            ! Determine factor for sum-square normalizaton:
            f = 1./sqrt(vdot(evtcorfn,evtcorfn,nBinc))
     
            ! Compute inner product with defined fns:
            do i=1,2
                finprod(i) = f*vdot(fcorfn(1,i),evtcorfn,nBinc)
            enddo
     
            return
            end
     
    *endfile member=acf_fnip