lapsf, lapsg

Given a scalar z, compute its Laplacian via Spherepack.

Synopsis

    procedure lapsf(
        z    : float,
        zlap : float
    )

    procedure lapsg(
        z    : float,
        zlap : float
    )

Arguments

z: scalar function array (input, two or more dimensions, last two dimensions must be nlat x nlon and input values must be in ascending latitude order).
zlap: Laplacian array (output, same dimensions as z, values will be in ascending latitude order)

Description

lapsf and lapsg both compute the Laplacian z and return it in the array zlap. lapsf operates on an equal (fixed) grid, and lapsg operates on a Gaussian grid.

Note: For the arrays whose last two dimensions are nlat x nlon, the rest of the dimensions (if any) are collectively referred to as nt. If the input/output arrays are just two dimensions, then nt can either be considered equal to 1 or nothing at all.

Arrays which have dimensions nt x nlat x nlon should not include the cyclic (wraparound) points when invoking the procedures and functions which use spherical harmonics (Spherepack).

For example, if an array x has dimensions nlat = 64 and nlon = 129, where the "129" represents the cyclic points, then the user should pass the data to the procedure/function via:

    z = sample ( x([...],:,0:nlon-2) )  ; does not include cyclic points

Error messages

If jer or ker is equal to:

1 : error in the specification of nlat
2 : error in the specification of nlon
4 : error in the specification of nt (jer only)

Reference Manual Control Panel

NG4.1 Home, Index, Examples, Glossary, Feedback, Ref Contents, Ref WhereAmI?

$Revision: 1.8 $ $Date: 1999/02/23 15:59:25 $