CDO

Dear CDO community,

I increased the number of iterations to 500, I have redone the computation but the execution of the EOF on the SST anomalies still does not converge.
So instead of Jacobi's algorithm, I used Danielson_lanczos' algorithm. The EOF run and there was no error message. Please, could you tell me if it is the solution to my problem?

Thank you in advance.

Best regards,

Siham

Hi Siham

i have the same problem, did you solve the problem?

Juliana.

juliana benjumea wrote:

Hi Siham

I have the same problem, did you solve the problem?

Juliana.

Dear Juliana,

Yeah, something like that. I reduced the area of interest using:
cdo sellonlatbox,long1,long2,lat1,lat2 <input.nc> <output.nc>

then after operating the EOF,
"
export CDO_SVD_MODE=jacobi
export CDO_WEIGHT_MODE=off
export CDO_MAX_JACOBI_ITER=100
export FNORM_PRECISION
cdo -b F64 eof,3 <anomaly.nc> <eigenval> <eofs>
"

I got the same message but with a reduced number of columns that didn't converge properly:

"statistics-module (Warning): Eigenvalue computation with one-sided jacobi scheme
did not converge properly. 1 of 630 pairs of columns did
not achieve requested orthogonality of 1e-12 "

I hope this could help you.

Best Regards,

Siham

Hi Siham

thanks for the explanation, I changed my script, but CDO_MAX_JACOBI_ITER does not change

"""
OpenMP: num_procs=8 max_threads=1 num_devices=0
cdo eof: Using CDO_SVD_MODE 'jacobi' from default
cdo eof: Using CDO_WEIGHT_MODE 'off' from default
cdo eof: Counting timesteps in ifile
cdo eof: Found 12000 timeSteps
cdo eof: Calculating 3 eigenvectors and 1586 eigenvalues in grid_space
cdo eof: Allocated eigenvalue/eigenvector structures with nts=12000 gridsize=1586
cdo eof: Calculating covar matrices for 1 levels of var0 (tos)
cdo eof: processing level 0
cdo eof: Using MAX_JACOBI_ITER 12 from default
cdo eof: Using FNORM_PRECISION 1e-12 from default
cdo eof: Finished one-sided jacobi scheme for eigenvalue computation after 12 iterations
statistics-module (Warning): Eigenvalue computation with one-sided jacobi scheme
did not converge properly. 833520 of 933661 pairs of columns did
not achieve requested orthogonality of 1e-12
cdo eof: Processed 19032000 values from 1 variable over 12000 timesteps [59.18s 86MB]
"""

Hi Siham,

OpenMP:  num_procs=8  max_threads=1  num_devices=0
cdo eof: Using CDO_SVD_MODE 'jacobi' from  default
cdo eof: Using CDO_WEIGHT_MODE 'off' from Environment
cdo eof: Counting timesteps in ifile
cdo eof: Found 12000 timeSteps
cdo eof: Calculating 3 eigenvectors and 1586 eigenvalues in grid_space
cdo eof: Allocated eigenvalue/eigenvector structures with nts=12000 gridsize=1586
cdo eof: Calculating covar matrices for 1 levels of var0 (tos)
cdo eof: processing level 0
cdo eof: Using MAX_JACOBI_ITER 100 from Environment
cdo eof: Using FNORM_PRECISION 1e-12 from default
cdo eof: Finished one-sided jacobi scheme for eigenvalue computation after 27 iterations
cdo eof: Processed 19032000 values from 1 variable over 12000 timesteps [114.07s 86MB]

It worked, I had something wrong.

Thanks !!!

Hi Juliana B,

what was the mistake? I have the same issue with CDO_MAX_JACOBI_ITER,
it remains the same even though I set new environment with

export CDO_MAX_JACOBI_ITER=100

Thank you
Christ

I apologize for my previous post,

I know my mistake, it supposed to be

export MAX_JACOBI_ITER=100

silly mistake,

Christ

Kindly assist me on how best to calculate seasonal anomalies (DJF, OND and JFM)  for geopotential height using a merged file geo79-2020.nc. My years of interest are 1989,1996,2003 and 2015.
Here are my steps for JFM
cdo yearmean -selmon,1,2,3 geo79-2020.nc 123yearmean.n
ccdo timmean 123yearmean.nc Tmean.nc
cdo -b 64 sub 123yearmean.nc Tmean.nc ano123.nc
To extract the years  I did use
cdo selyear.2015 ano123.nc ano123.15.nc
cdo selyear.2003 ano123.nc ano123.03.nc
cdo selyear.1996 ano123.nc ano123.96.nc
cdo selyear.1989 ano123.nc ano123.89.nc
Are these steps the right way?
Abubakar

Hi Abubakar,

please, next time create a "new message" because your question does not belong to this one.

It looks good to me but there are some typos

cdo yearmean -selmon,1,2,3 geo79-2020.nc 123yearmean.n
cdo timmean 123yearmean.nc Tmean.nc
cdo -b 64 -sub 123yearmean.nc Tmean.nc ano123.nc

cdo selyear,2015 ano123.nc ano123.15.nc
cdo selyear,2003 ano123.nc ano123.03.nc
cdo selyear,1996 ano123.nc ano123.96.nc
cdo selyear,1989 ano123.nc ano123.89.nc