[ferret_users] Re: [ferret_users] Vertical regridding without interpolation

[mcaillau <Matthieu.Caillaud@xxxxxxxxxx>]

On my first grid i have 5 vertical levels and the thickness vary in 
time.
I want to map these levels on a on second grid with z-axis (for instance 
30 z-levels). but i dont want the data from my first grid to be 
interpolated on the second. For each cell grid of the second grid, i 
want to compute the depth and then look for the corresponding value in 
one of the 5 intervals of depth of the first grid. And i have to do it 
at each time step.

I dont konw if it's clear...

Thanks

Matthieu

Le 2013-08-09 18:06, Ansley Manke a écrit :
> Hi Matthieu,
>  Do you mean that the levels in your grid correspond to known depths,
> so that you would like to simply assign a depth to each level?  If
> that is the case, then use the @ASN transformation to put the data
> onto the depth axis. Make sure there are the same number of depths as
> levels, for instance:
>
> > yes? define axis/z=/units=meters/depth zdepths =
> > {2,5,10,15,20,30,50,100}
> > yes? let/units="`temp,return=units`" temp_on_depth =
> > temp[gz=zdepths@ASN]
>  and note that on the DEFINE AXIS command, you could use /EDGES so
> that you define the edges of the grid cells instead of the grid cell
> centers. For unequally spaced grids, this is often the better choice.

>  -Ansley
>
> On 8/9/2013 1:57 AM, mcaillau wrote:
>
> > Hi Ferret users,
> >
> > I have data on a vertical level axis (level-grid) and i would like
> > to regrid it to a regular z axis.
> > I have the thickness of each level (which vary in time).
> >
> > I know that ZAXREPLACE would do it but i dont want my data to be
> > interpolated on the z-axis. I am looking for the following
> > transformation :
> > for each grid cell of my z-axis (so at a given depth) it will
> > affect the value at the same depth from my level-grid.
> >
> > Thank in advance for your help
> >
> > Matthieu