Hi,
Just as a warning, suppressing the bad partition function error is not good
practice since it is known that they are, you know, bad. Standard tests in
ARTS fail by several tenths of Kelvin because the partition functions in
ARTS are that bad. Just run with the provided tips xml-files instead,
because if your temperatures are lower than 70 K or higher than 3000 K you
probably have another problem.
With hope,
//Richard
2018-09-17 10:31 GMT+02:00 이병석 <cb...@aracnt.com>:
> Hello Simon Pfreundschuh,
>
> Thank you for your reply.
>
> I have employed both of the suggestions and still get the irregular
> errors. From the same controlfile modified in the previous email, I have
> included and changed to the following lines:
>
> OEM(method="lm",
> max_iter=15,
> display_progress=1,
> lm_ga_settings=[100,5,2,1000,1,99])
>
> and
>
> AgendaSet( inversion_iterate_agenda ){
>
> xClip(ijq = 0, limit_low = 150.0, limit_high = 350)
>
> Ignore(inversion_iteration_counter)
> # Map x to ARTS' variables
> x2artsStandard
>
> # To be safe, rerun checks dealing with the atmosphere
> atmfields_checkedCalc
> atmgeom_checkedCalc
>
> # Calculate yf and Jacobian matching x.
> yCalc( y=yf )
>
> # Add baseline term
> VectorAddVector( yf, yf, y_baseline )
>
> # This method takes cares of some "fixes" that are needed to get the
> Jacobian
> # right for iterative solutions. No need to call this WSM for linear
> inversions.
> jacobianAdjustAndTransform
> }
>
> I included both of the suggestions, and from there
> increased the maximum number of iterations to 15 and set the temperature
> limits to be between 150
> K and 350 K. All other lines remain the same, including the input
> absorption line and atmospheric fields data.
>
> Now I irregularly get the errors during the OEM computation as before, of
> t_field having NaN values or of bad partition function warning (which
> happens for any t_field value outside between 150 K and 300 K). While the
> bad partition function warning could be suppressed in the code, it seems
> that the same problem as before persists.
>
> Could you please look into this issue a little more? I am not sure how to
> tackle the problem.
>
> Thank you for your service.
>
> Regards,
>
>
> Byungsuk Lee
>
> ARA Consulting & Technology
>
> 30 Songdomirae-ro D-1510, Yeonsu-gu, Incheon 21990, South Korea
>
>
>
> -----Original Message-----
> *From:* "Simon Pfreundschuh"<simon.pfreundsc...@chalmers.se>
> *To:* "이병석"<cb...@aracnt.com>; "arts_users...@mailman.rrz.uni-hamburg.de"<
> arts_users...@mailman.rrz.uni-hamburg.de>;
> *Cc:*
> *Sent:* 2018-09-14 (금) 15:13:55
> *Subject:* Re: [arts-users] ARTS OEM
>
> Hi Byungsuk Lee,
>
> It is a bit surprising that these errors occur irregularly, since there is
> no randomness
> in the test setup. However, if you are running retrievals with external
> observation data
> it may well happen that the iteration ends up in a state that produces
> invalid values.
>
> For your temperature retrieval I would recommend one or both of the
> following solutions:
>
> 1. Use the Levenberg-Marquardt (LM) iteration scheme: Using the LM scheme
> with a high start
> value for the gamma parameter can help avoid reaching invalid values
> when the forward
> model is non-linear:
>
> OEM(method="lm",
> max_iter=5,
> display_progress=1,
> lm_ga_settings=[100,5,2,1000,1,99])
>
> 2. Clip the x-vector: Using the xClip WSM inside your inversion iterate
> agenda you can force the
> x vector to contain only temperatures within a certain range. If you
> use this approach you
> should check that none of the retrieved temperatures in your final
> state are clipped otherwise your
> results may not be valid.
>
> AgendaSet( inversion_iterate_agenda ){
>
> xClip(ijq = 0, limit_low = 100.0)
> Ignore(inversion_iteration_counter)
> # Map x to ARTS' variables
> x2artsStandard
>
> # To be safe, rerun checks dealing with the atmosphere
> atmfields_checkedCalc
> atmgeom_checkedCalc
>
> # Calculate yf and Jacobian matching x.
> yCalc( y=yf )
>
> # Add baseline term
> VectorAddVector( yf, yf, y_baseline )
>
> # This method takes cares of some "fixes" that are needed to get the
> Jacobian
> # right for iterative solutions. No need to call this WSM for linear
> inversions.
> jacobianAdjustAndTransform
> }
>
>
> Regards,
>
> Simon
>
> ------------------------------
> *From:* arts_users.mi-boun...@mailman.rrz.uni-hamburg.de <
> arts_users.mi-boun...@mailman.rrz.uni-hamburg.de> on behalf of 이병석 <
> cb...@aracnt.com>
> *Sent:* Friday, September 14, 2018 2:31:25 AM
> *To:* arts_users...@mailman.rrz.uni-hamburg.de
> *Subject:* [arts-users] ARTS OEM
>
> Dear ARTS users,
>
> I am writing to address a question with the use of OEM in the ARTS
> development version.
>
> From the "TestOEM.arts" in "ARTS/controlfiles/artscomponents/oem", this
> time I changed the codes as follows.
>
> 1) From (line 115):
> retrievalAddAbsSpecies(
> species = "O3",
> unit = "vmr",
> g1 = p_ret_grid,
> g2 = lat_grid,
> g3 = lon_grid
> )
> To:
> retrievalAddTemperature (
> g1 = p_ret_grid,
> g2 = lat_grid,
> g3 = lon_grid,
> hse = "off" )
>
> 2) From (line 125):
> VectorSetConstant(vars, nelem, 1e-12)
> DiagonalMatrix(sparse_block, vars)
> covmat_sxAddBlock(block = sparse_block)
> To:
> VectorSetConstant(vars, nelem, 0.1)
> DiagonalMatrix(sparse_block, vars)
> covmat_sxAddBlock(block = sparse_block)
>
> 3) From (line 37):
> NumericSet( f_start, 110.436e9 )
> NumericSet( f_end, 111.236e9 )
> IndexSet( nf, 801 )
> IndexSet( np, 81 )
> To:
> NumericSet( f_start, 110.436e9 )
> NumericSet( f_end, 111.236e9 )
> IndexSet( nf, 18 )
> IndexSet( np, 18 )
>
> 4) From (line 42):
> VectorNLinSpace( f_grid, nf, f_start, f_end )
> VectorNLogSpace( p_grid, 361, 500e2, 0.1 )
> VectorNLogSpace( p_ret_grid, np, 500e2, 0.1 )
> To:
> VectorNLinSpace( f_grid, nf, f_start, f_end )
> VectorNLogSpace( p_grid, 18, 500e2, 0.1 )
> VectorNLogSpace( p_ret_grid, np, 500e2, 0.1 )
>
> Overall, I changed the ozone VMR retrieval to temperature retrieval and
> reduced the number of frequencies and pressure layers.
>
> When I run the controlfile multiple times, I irregularly get errors. The
> error messages are
>
>
> Run-time error in oem computation: Forward Model Evaluation Error
>
> Run-time error in agenda: inversion_iterate_agenda
>
> Run-time error in method: atmfields_checkedCalc
>
> The variable *t_field* contains one or several NaNs. This is not
> allowed!
>
>
>
> or
>
>
>
> All temperatures in *t_field* must be > 0.
>
> or seldom the bad partition function warning.
>
> Here are my questions:
> 1) Is this an anticipated error, simply coming from failing to find a
> converging solution? Is it expected that the OEM sometimes throws an error
> as above?
> 2) Are there mechanisms (e.g. workspace methods) within the ARTS that can
> prevent the t_field or vmr_field from becoming either negative or NaN
> during the OEM iterations?
>
> Thank you for your assistance.
>
> Regards,
>
>
> Byungsuk Lee
>
> ARA Consulting & Technology
>
> 30 Songdomirae-ro D-1510, Yeonsu-gu, Incheon 21990, South Korea
>
> *Email: * cb...@aracnt.com
>
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