[daip] FRING memory requirements

[Eric Greisen]

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 delays
>>> FRING1:  Writing SN table    1
>>> FRING1:  Time=   0/ 02 28 14, Polarization = 1
>>> FRING1:  QINIT: did a GET  of      5120 Kwords, OFF   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.

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.

Eric Greisen