Hi Sophie, Billy gives good arguments for why you might not want to use one of the scat2grid_yz functions at all. I just want to add that the way you're reading your data is the reason for the result being in i, y, and z (and it shows where we need to clarify the documentation.) Your data are lists of values on an I axis. If you look at the function details yes? show function SCAT2GRIDLAPLACE_YZ SCAT2GRIDLAPLACE_YZ(YPTS,ZPTS,F,YAXPTS,ZAXPTS,CAY,NRNG) Use Laplace interpolation to grid scattered data to a YZ grid. YPTS: y-coordinates of scattered input triples ZPTS: z-coordinates of scattered input triples F: F(Y,Z) 3rd component of scattered input triples. May be fcn of X and/or T YAXPTS: Y axis coordinates of a regular output grid ZAXPTS: Z axis coordinates of a regular output grid CAY: Interpolation parameter: CAY NRNG: Interpolation parameter: NRNG You will see that the third argument "F(Y,Z) may be fcn of X and/or T". This means that one could use the function to grid a whole set of Y-Z slices, at different values of X. (or, think of a whole set of x-y planes at different Z levels with one of the scat2grid*xy functions). If you do this problem with scat2gridgauss_yz, make the lat, depth, temp values be on a Y or Z axis. let ylat = YSEQUENCE(lat) let ydepth = YSEQUENCE(depth) let ysalt = YSEQUENCE(salt) let salinite =SCAT2GRIDGAUSS_YZ(ylat,ydepth,ysalt,y[gy=yaxs],z[gz=zaxs],2,2,2,2) Ansley Sophie Cravatte wrote: Dear Ferret users, I can't figure out how to use the function SCAT2GRIDGAUSS_YZ to grid scattered data to a YZ grid. Here is my script: define axis/y=20S:5S:1/units=degrees yaxs define axis/z=0:500:1/units=meters/depth zaxs SET DATA/EZ/var="lat,depth,temp,salt,o1,o2,dens" r165e.dat let salinite =SCAT2GRIDGAUSS_YZ(lat,depth,salt,y[gy=yaxs],z[gz=zaxs],2,2,2,2) And instead of having a 2-D YZ field for salinite, I got a 3-D i,Y,Z field, and of course with stupid values. What's wrong in my script? What didn't I understand? Thanks a lot for your help, Sophie |