interpolation code for 3d data !!

From: Pradipta Bandyopadhyay <pradipta_at_cgl.ucsf.edu>
Subject: interpolation code for 3d data !!
Date: Tue, 1 Jul 2003 16:45:30 -0700 (PDT)

Hi,
   I am looking for a code(in fortran) for interpolation of a large set
 of 3 dimensional data (on an eqaully spaced grid). I tried the polynomial
 routine in numerical recipe -but it is very poor for my data. Probably
 spline or hermite polynomial based interpolation scheme would be the best.
 I would appreciate any help.
 thanks.
          Pradipta