SUBROUTINE EXTRAP1D_LAPSERATE_X(numInterpSets, srcNumLevels, 
destNumLevels, src_ijDim, dst_ijDim, vLevelSource, stateSource, stateDerivSource, 
posnDestInSrc, vLevelDestn, stateDestn, stateDerivDestn, extrapEnableDown, 
extrapEnableUp, extrapGuideDown, extrapGuideUp, flux, numExtArraysIn,
numExtArraysOut, ExtArraysIn, ExtArraysOut)

integer, intent(in) :: numInterpSets
integer, intent(in) :: srcNumLevels
integer, intent(in) :: destNumLevels

integer, intent(in) :: src_ijDim
integer, intent(in) :: dst_ijDim

real, dimension(src_ijDim, srcNumLevels), intent(in) :: vLevelSource
real, dimension(src_ijDim, srcNumLevels), intent(in) :: stateSource
real, dimension(src_ijDim, srcNumLevels), intent(in) :: stateDerivSource

integer, dimension(dst_ijDim, destNumLevels), intent(in) :: posnDestInSrc
real, dimension(dst_ijDim, destNumLevels), intent(in) :: vLevelDestn
real, dimension(dst_ijDim, destNumLevels), intent(out) :: stateDestn
real, dimension(dst_ijDim, destNumLevels), intent(out) :: stateDerivDestn

logical, intent(in) :: extrapEnableDown, extrapEnableUp
real, intent(in) :: extrapGuideDown, extrapGuideUp

external flux

integer, intent(in) :: numExtArraysIn
integer, intent(in) :: numExtArraysOut
real, dimension(src_ijDim, numExtArraysIn), intent(in)  :: ExtArraysIn
real, dimension(dst_ijDim, numExtArraysOut), intent(out) :: ExtArraysOut
DESCRIPTION 
For each destination level that is outside the set of source levels, a state value
(but not a derivative) is extrapolated.  The extrapolated value lies on a straight 
line that passes through the closest source level with the slope, extrapGuideDown 
(for a destination level that lies before [i.e. has a smaller index than] the source 
levels) or extrapGuideUp (for a destination level that lies after the source levels). 
Values that would be interpolated are untouched by the routine.

Author: Jeff Blezius - revised Oct 2003
ARGUMENTS

It can be noted that the arguments to all of the Interp1D_* and Extrap1D_* routines are identical, for ease of switching a call from one to another of them. You should examine the generic description of the arguments. The following are uses of the generic arguments that are specific to this routine:

Input:
extrapGuideDown	lapse rate below the vLevelSource values; i.e. the derivative of the state value with respect to the vertical level
extrapGuideUp	lapse rate above the vLevelSource values; i.e. the derivative of the state value with respect to the vertical level
flux	unused
ExtArraysIn	unused
Output:
stateDerivDestn(dst_ijDim, dstNumLevels)	unused
ExtArraysOut	unused

SEE ALSO