[daip] FRING memory requirements
Amy Mioduszewski
amiodusz at nrao.edu
Tue May 12 18:05:23 EDT 2009
Hi Ingyin,
So I am confused about what you are trying to do. Why do you need multiband
delays? I assumed you are trying to do a geodetic type calibration. For this
you need calibrators observed all over the sky and would not need to observe
those with narrow channels.
Amy
Ingyin Zaw wrote:
>> 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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