c     user amplitude subroutine
      Subroutine uamp(
C          passed in for information and state variables
     *     ampName, time, ampValueOld,  dt,  nSvars, svars, lFlagsInfo,
     *     nSensor, sensorValues, sensorNames, jSensorLookUpTable, 
C          to be defined
     *     ampValueNew, 
     *     lFlagsDefine,
     *     AmpDerivative, AmpSecDerivative, AmpIncIntegral,
     *     AmpIncDoubleIntegral)
      
      include 'aba_param.inc'

C     svars - additional state variables, similar to (V)UEL
      dimension sensorValues(nSensor), svars(nSvars)
C      character*80 sensorNames
      character*80 ampName

C     time indices
      parameter (iStepTime        = 1,
     *           iTotalTime       = 2,
     *           nTime            = 2)
C     flags passed in for information
      parameter (iInitialization   = 1,
     *           iRegularInc       = 2,
     *           nFlagsInfo        = 2)
C     optional flags to be defined
      parameter (iComputeDeriv       = 1,
     *           iComputeSecDeriv    = 2,
     *           iComputeInteg       = 3,
     *           iComputeDoubleInteg = 4,
     *           iStopAnalysis       = 5,
     *           iConcludeStep       = 6,
     *           nFlagsDefine        = 6)
      dimension time(nTime), lFlagsInfo(nFlagsInfo),
     *          lFlagsDefine(nFlagsDefine)
      dimension jSensorLookUpTable(*)

      parameter(timeStarSecStep = 1.0d0)



C ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
C     User code to compute  ampValue = F(sensors)
C ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

c     get sensor values first
      iR_VR3  = ivGetSensorID('SensorVR3', jSensorLookUpTable)
      valueR_VR3  = sensorValues(iR_VR3)      
      
      if (lFlagsInfo(iInitialization).eq.1) then
        ampValueNew =  2407.
      else
c        ampValueNew = 1. + sqrt(valueR_VR3)
	    ampValueNew = (4E-12 * (valueR_VR3)^6) - (8E-09 * (valueR_VR3)^5) + (6E-06 * (valueR_VR3)^4) - (0,0017 * (valueR_VR3)^3) + (0,251 * (valueR_VR3)^2) - (13,84 * (valueR_VR3)) + 2407,4
      endif
      write (6,*)'rps=', valueR_VR3,'amp=',ampValueNew
      
      return
      end