Hi Neks, I am using the routine " Grid 2 Grid Interpolation <http://lists.mcs.anl.gov/pipermail/nek5000-users/2010-September/001004.html>" , it does interpolate data between two meshes, but there is another problem: Both the "base.fld" and "new_geo.fld" are double-precision, however, the interpolated "new.fld" is single precision. show the head here: #std 4 8 8 8 31200 31200 0.1969999999996E+03 0 0 1 XUPT - I have already active the parameter(63) to 8, trying to save the double-precision result. Any one have a solution? thanks! Wei -