The OPAL Discussion Forum

[Simon Friederich <s.friederich AT uni-mainz.de>]

Dear all,

@Jochem, thank you. Simply "touching" the *.data file did the trick, like you said:

touch /media/sf_Seafile_OPAL/example_sampler/example_sampler_drift.data

Now I have another 'problem', which i encounter trying to get the sampler example from the OPAL wiki run

(please find the files here (the mailing list distributor does not allow me to send 2MB text files apparently):

https://seafile.rlp.net/d/68fced4ed03d4c51af7c/

)

File	Relative Location (.^= media/sf_Seafile_OPAL/example_sampler_opalwiki/)
sampler_opalwiki.in	.
sampler_data	.
Ring.tmpl	./templates/
Cav1.dat, Cav3.dat, s03av.nar	./templates/ (tried also ./Fieldmaps/)

Error:

OPAL{0}> opal sampler_opalwiki.in --inputfile=Ring.tmpl --outfile=RingSample --outdir=RingSample --num-masters=1 --num-coworkers=1 --restartstep=-2147483648 --jsonDumpFreq=18446744073709551616 --nsamples=6 --simtmpdir=/media/sf_Seafile_OPAL/example_sampler_opalwiki/RingSample --templates=/media/sf_Seafile_OPAL/example_sampler_opalwiki/template

  ✔ 1 objectives

  ✔ 2 dvars

  3 (PID: 3720) ▶ Worker

  2 (PID: 3719) ▶ Worker

  0 (PID: 3717) ▶ Pilot

  1 (PID: 3718) ▶ Sampler

Warning: argument "one-pilot-converge" not found! Using default value (0).

Warning: argument "restartfile" not found! Using default value ().

boost::filesystem::create_symlink: File exists: "/media/sf_Seafile_OPAL/example_sampler_opalwiki/Fieldmaps/data", "/media/sf_Seafile_OPAL/example_sampler_opalwiki/RingSample/0/data"

in OpalSimulation::createSymlink()

Ippl> CommMPI: Parent process waiting for children ...

Ippl> CommMPI: Initialization complete.

Error>

Error> *** User error detected by function "Cyclotron::getFieldFromField"

Error>     failed to open file 's03av.nar', please check if it exists

Error>     failed to open file 's03av.nar', please check if it exists

If I understand correctly:
The sampler creates the directory "./RingSample/0/" which contains i.a. "Ring.in" which seems to be a copy of "./templates/Ring.tmpl";
Nevertheless it tries to find the fieldmaps also within "./RingSample/0/" but they are not copied there automatically. I also put the fieldmaps (Cav1.dat, Cav3.dat and s03av.nar) in ./Fieldmaps/ but that has no effect either.

Best regards,
Simon

P.S.: Please don't tell me, that I have to use absolute paths :-)

-----------------------------------
Dr. Simon Friederich
Helmholtz-Institut Mainz
Kollaboration B/ACID
Johannes Gutenberg-Universität Mainz
Staudingerweg 18
55128 Mainz, Deutschland

Tel.: +49 (0)6131 39-23160
E-Mail: s.friederich AT uni-mainz.de
-----------------------------------

Am 17.02.2020 um 11:15 schrieb Dr. Simon Friederich:

Dear Bettina and Jochem,

Thank you very much for your quick answers. I'll check as soon as possible you suggestions and will report back.

Best regards,
Simon

-----------------------------------
Dr. Simon Friederich
Helmholtz-Institut Mainz
Kollaboration B/ACID
Johannes Gutenberg-Universität Mainz
Staudingerweg 18
55128 Mainz, Deutschland

Tel.: +49 (0)6131 39-23160
E-Mail: s.friederich AT uni-mainz.de
-----------------------------------

Am 17.02.2020 um 09:41 schrieb Kuske, Bettina:

Hi Simon,

 

can you please send your input file, so we can have a look at it?

To my knowledge, the sampler does not work for a single variable.

Try if it works for two variables, if yes, that was the problem.

If no, send your input file.

 

Have a nice day,

Bettina

 

From: opal-request AT lists.psi.ch <opal-request AT lists.psi.ch> On Behalf Of Dr. Simon Friederich
Sent: Montag, 17. Februar 2020 08:56
To: opal AT lists.psi.ch
Subject: [Opal] Exception using sampler

 

Dear all,

Please let me shortly introduce myself:
My name is Simon Friederich. I am working at the institute of nuclear physics in Mainz (Germany) and I have just recently started simulating with OPAL. My goal is to simulate the low-energy beam apparatus of our upcoming Mainz Energy-recovering Superconducting Accelerator (MESA).

I gathered some experience starting with a simple example: I sent a gaussian distributed bunch through a 1m drift (electrons, 100keV, I=1mA) and watched the emittance growth in particular.

My next step was to use the 'sampler' and change some variable (e.g. the CUTOFFR parameter of my injected distribution). But I get the following exception message leading to a simulation stop:

OPAL{0}> opal sampler.in --inputfile=example_sampler_drift.tmpl --outfile=samplerout --outdir=samplerout --num-masters=1 --num-coworkers=1 --restartstep=-2147483648 --jsonDumpFreq=18446744073709551616 --nsamples=1 --simtmpdir=/media/sf_Seafile_OPAL/example_sampler/samplerout --templates=/media/sf_Seafile_OPAL/example_sampler/. 

  ✔ 1 objectives

  ✔ 1 dvars

  0 (PID: 1686) ▶ Pilot

  1 (PID: 1687) ▶ Sampler

  2 (PID: 1688) ▶ Worker

Warning: argument "one-pilot-converge" not found! Using default value (0).

  3 (PID: 1689) ▶ Worker

Exception while running simulation: The data file 'example_sampler_drift.data' 

     doesn't exist in directory '/media/sf_Seafile_OPAL/example_sampler'

Stop Pilot..

OPAL{0}> * End of input stream "sampler.in".

Stop Worker..

Stop Sampler..

Stop Worker..

I have tested the "example_sampler_drift.tmpl" with a fixed value of CUTOFFR and
it runs through. I get the results within the 'data' directory. No *.data file though.

Then I tried the example from https://gitlab.psi.ch/OPAL/Manual-2.2/blob/master/sampler.asciidoc but it prints out the same exception message:
Exception while running simulation: The data file 'Ring.data' doesn't exist in directory '/media/sf_Seafile_OPAL/example_sampler_opalwiki'

Is the *.data-file something specific coming from the sampler?
Do you have an idea of what I am missing here?

Thank you very much in advance.
Best regards,
Simon

-----------------------------------

Dr. Simon Friederich

Helmholtz-Institut Mainz

Collaboration B/ACID

Johannes Gutenberg-Universität Mainz

Staudingerweg 18

55128 Mainz, Germany

phone: +49 (0)6131 39-23160

E-Mail: sifriede AT uni-mainz.de

-----------------------------------

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