[daip] FRING memory requirements
Ingyin Zaw
iz6 at cosmo.nyu.edu
Tue May 12 18:01:55 EDT 2009
> Ingyin Zaw wrote:
>> On Thu, 7 May 2009, Eric Greisen wrote:
>>
>> > Ingyin Zaw wrote:
>> > > Hello,
>> > >
>> > > I checked setapmax. It was set to 528 Mbytes. I changed it to the
>> > > maximum
>> > > allowed:
>> > > > setmaxap(0)
>> > > AIPS 1: SETMAXAP: current max dynamic AP is 6144.000 Mbytes
>> > > AIPS 1: SETMAXAP: allowed range is 20 to 6144 Mbytes
>> > >
>> > > I still get the same memory error as below.
>> > >
>> > > The fring parameters I've set (which are not defaults) are:
>> > > calsour '2145+067'
>> > > refant 6
>> > > solint 0
>> > > aparm 3 0 0 0 2 0
>> > > dparm 3 1 1 4.1 0
>> > >
>> > > (docalib -1; flagver 0; doband -1).
>> > >
>> > > Thanks,
>> > > Ingyin
>> > >
>> > >
>> > >
>> > > On Wed, 6 May 2009, Eric Greisen wrote:
>> > >
>> > > > Ingyin Zaw wrote:
>> > > > > Hello,
>> > > > >
>> > > > > I'm trying to run FRING with aparm(5)=2 to solve for multiband
>> > > > > and single
>> > > > > band delays on a file with 256 channels and 8 IFs (experiment
>> > > > > BK114A). I
>> > > > > get the following error.
>> > > > >
>> > > > > FRING1: Task FRING (release of 31DEC09) begins
>> > > > > FRING1: You are using a non-standard program
>> > > > > FRING1: Doing no flagging this time
>> > > > > FRING1: Selecting the data
>> > > > > FRING1: Dividing data by source flux densities
>> > > > > FRING1: Determining solutions
>> > > > > FRING1: Doing Least Squares fits for multi- and single-band
>> > > > > FRING1: delays
>> > > > > FRING1: Writing SN table 1
>> > > > > FRING1: Time= 0/ 02 28 14, Polarization = 1
>> > > > > FRING1: QINIT: did a GET of 5120 Kwords, OFF
>> > > > > FRING1: 11963214967809
>> > > > > FRING1: FRNSRC: MEMORY TOO SMALL FOR SPECIFIED FFT SEARCH
>> > > > > FRING1: REDUCE DELAY AND/OR RATE WINDOW OR AVERAGE IN
>> > > > > FRING1: FREQUENCY OR USE A SHORTER SOLINT
>> > > > > FRING1: Purports to die of UNNATURAL causes
>> > > > > FRING1: rglinux9 31DEC09 TST: Cpu= 0.9 Real= 1
>> > > > > IO= 86
>> > > > > AIPS 1: Resumes
>> > > > > AIPS 1: RETURN CODE 2 RECEIVED: STOPPING
>> > > > >
>> > > > > I have set dparm 3 1 1 4.1 0. It seems strange that it fails for
>> > > > > such a
>> > > > > small search window. It fails even when the search window is set
>> > > > > to 0.1
>> > > > > nsec and 0.1 mHz. I'm not applying any calibrations or bandpass.
>> > > > >
>> > > > > I'm running 31 DEC 09, 64 bit AIPS on a machine with following
>> > > > > specifications:
>> > > > > Linux rglinux9.cfa.harvard.edu 2.6.18-128.1.1.el5 #1 SMP Mon Jan
>> > > > > 26
>> > > > > 13:58:24 EST 2009 x86_64 x86_64 x86_64 GNU/Linux
>> > > > >
>> > > > > I have seen the same problem on 31 DEC 09, 32 bit AIPS as well
>> > > > > on an
>> > > > > experiment with 512 channels and 8 IFs (BB242D).
>> > > > >
>> > > > > I have made a FITS file of only the source I used for FRING for
>> > > > > testing.
>> > > > > It's available by ftp from cfa-ftp.harvard.edu,
>> > > > > User = anonymous, password = <youremailaddress>.
>> > > > > The file is located at: incoming/lincoln/BK114A_2145.FITS
>> > > > >
>> > > > > Please let me know what I can do to be able to run FRING with
>> > > > > aparm(5)=2.
>> > > > Needless to say FRING should not do this - I note that it only
>> > > > asked for 20 Megabytes of AP memory. It is supposed to ask for
>> > > > what it actually needs if you allow it to do so. Have you run
>> > > > SETMAXAP with a small limit? I would recommend set your max AP to
>> > > > 0.5 or 1 Gbyte on your 64-bit computer.
>> > > >
>> > > > If that does not work, send me your inputs and we will fetch the
>> > > > file and look at the problem.
>> > > >
>> > > > Eric Greisen
>> > > >
>> > > >
>> > You have asked for an FFT on the frequency axis of length 131072 or
>> > perhaps it is 524288 - I do not know the details enough to be sure.
>> > AIPS now does FFTs up to 32768 and we have no plans to allow larger in
>> > the near term. I will repair the error message which now is only about
>> > allowed size of FFTs (it used to mean what it says) and repair the limit
>> > in FRING which is currently lower than it has to be. But that will not
>> > allow you to do what you are trying to do. There are aips memos which
>> > describe what you should do to accomplish what you need to accomplish.
>> I tried to reproduce the 131072 number and come up short. I have an
>> experiment (BK114A, 256 channels, 8 IFs) with 500 MHz total bandwidth with
>> ~ 60 kHz channels which would seem, at most, to have a frequency axis of
>> length 16384. Even for 512 channels and 8 IFs, I get a frequency axis of
>> length 32768, which is within AIPS capabilities. Could you point out where
>> my calculations are different from yours.
>>
>> > See the aips web page:
>> > http://www.aips.nrao.edu/
>> > and read AIPS Memo 110.
>> >
>> > You will need to run FRING an IF at a time effectively and then solve
>> > for multi-band delay with MBDLY.
>> Thanks for pointing me to the memo. It says that FRING with aparm(5)=2 is
>> better than aparm(5)=0 + MBDLY when sources are weaker. We observe at 22
>> GHz and our calibrators are relatively weaker, so we'd like the option of
>> running with aparm(5)=2, if possible.
>>
>> > Eric Greisen
>> >
>> Thanks,
>> Ingyin
>>
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> Hi Ingyin,
>
> I am coming into this late so I apologize if don't understand something. How
> weak are your calibrators? If your calibrators are weak wouldn't it be
> better to average some channels? Why do you need 512 channels anyway? The
> multiband delay is looking at the delay between the IFs, the singleband delay
> is not calculated.
>
> Amy
Hi Amy,
I'm observing H20 masers at 22 GHz. I have so many channels (256 in the
current dataset) because the maser lines are only ~1 km/s wide. I did
average 8 channels using AVSPC but was getting ringing when I applied a BP
table. That problem seems to be resolved now so I can run FRING with
aparm(5)=2 on the averaged file (with 32 channels).
Thanks,
Ingyin
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