Re,
Thank you Satyesh for your answer.
Unfortunatelly, my variable does not have a time dimension.
So spread the work into parts on L dimension won't help.
My variable is defined as follows:
dimensions:
lon = 36000 ;
lat = 18000 ;
If I use JLIMITS then I get this error message:
save/clobber/file="($03)"/JLIMITS=1:300 mask
!-> LIST/FORMAT=CDF/clobber/file="tyty.nc"/JLIMITS=1:300 mask
LISTing to file tyty.nc
**ERROR: invalid command: Does not encompass data to be written: JLIMITS=1:300
Variable: MASK
The complete test is:
gdal_rasterize -a area -te -180 -90 180 90 -tr 0.01 0.01 i/GSHHS_i_L1.shp mask_i_L1_0.01.nc
---> Rasterize the vectors shorelines into a 0.01° gridded land/water variable (4.9Go).
Now my purpose is to create coarser resolutions (0.05, 0.25, 0.5) of this variable with percent of land/water occupation.
It can be nicelly done with ferret regridding transformations such as: [G=MYGRID@AVE]
The script runs with a region but not for the entire globe.
use mask_i_L1_0.01.nc
let mask1 = if band gt 1 then 1 else 0
def axis/x=-180:180:0.50/edges/units=degrees_east myxaxis
def axis/y=-90:90:0.50/edges/units=degrees_north myyaxis
def grid/x=myxaxis/y=myyaxis mygrid
let mask = mask1[G=MYGRID@AVE]
save/clobber/file=LandWater_0.50.nc mask
Patrick
--
Data Analysis and Visualization Engineer / Project Manager
LSCE/IPSL, CEA-CNRS-UVSQ laboratory
LSCE - Climate and Environment Sciences Laboratory
IPSL - Institut Pierre Simon Laplace
--
De: "Satyesh Ghetiya" <satyeshghetiya@xxxxxxxxx>
À: "Patrick Brockmann" <patrick.brockmann@xxxxxxxxxxxx>
Cc: "ferret users" <ferret_users@xxxxxxxx>
Envoyé: Lundi 20 Mai 2019 15:33:42
Objet: Re: [ferret_users] memory problem with large file when regredding
Dividing data with many indeces (e.g. L or I or J or K) is good method to handle saving of large files.
I don't know how many L values are there, but suppose you have total values of L = Lmax (i.e. L=1:Lmax), then you may try following:
save/clobber/file=
file_0.1.nc/llimit=Lmax/l=1 mask ! put Lmax as a number say 365 or something .....
repeat/range=2:Lmax/name=aa (save/append/file=
file_0.1.nc mask[=`aa`])
Hope it works. (LLIMITS can be used for I also, for e.g. ILIMIT)
Hi all,
I have a 5Go variable at 0.01x0.01 resolution and I would like to save it at a coarser resolution.
My regridding script cannot be run because it requires too much memory.
Is there a strategy to run it ?
I have tried to save it with different /append calls but cannot figure out
because anunlimited dimension seems to be possible only for time dimension (L).
Here are the simplified lines from my script for a regredding from 0.01 to 0.1°
!============================
def axis/x=-180:180:0.1/edges/units=degrees_east myxaxis
def axis/y=-90:90:0.1/edges/units=degrees_north myyaxis
def grid/x=myxaxis/y=myyaxis mygrid
let mask = mask1[G=MYGRID@AVE]
!============================
Any help would be appreciated.
Regards
Patrick
--
Data Analysis and Visualization Engineer / Project Manager
LSCE/IPSL, CEA-CNRS-UVSQ laboratory
LSCE - Climate and Environment Sciences Laboratory
IPSL - Institut Pierre Simon Laplace
--
--