[daip] Problem with 31DEC05 IMAGR with CMETHOD ''

[Subhashis Roy]

Hi,

It appears that with CMETHOD '', the present algorithm (07DEC05) is not correct to
choose the fastest method when IMSIZE=128i. It is not selecting GRID at
all in this case (It appears to be fine when IMSIZE=256).  
(this run is on i386 compiled with gcc-2.95.3).

These are 3 cases during one run of IMAGR with 12 fields and IMSIZE=128
for each field.
----------------------
localh> IMAGR1: Resuming Clean with     8563 filtered components
localh> IMAGR1: VISDFT: Begin DFT component subtraction
localh> IMAGR1: I Polarization model processed
localh> IMAGR1: Field   1 min =  -15.3 MilliJy,max =   20.2 MilliJy
localh> IMAGR1: Field   2 min =  -10.6 MilliJy,max =   10.6 MilliJy
localh> IMAGR1: Field   3 min =  -15.5 MilliJy,max =   13.6 MilliJy
localh> IMAGR1: Field   4 min =  -20.9 MilliJy,max =   15.4 MilliJy
localh> IMAGR1: Field   5 min =  -17.9 MilliJy,max =   13.9 MilliJy
localh> IMAGR1: Field   6 min =  -12.2 MilliJy,max =   12.2 MilliJy
localh> IMAGR1: Field   7 min =   -7.8 MilliJy,max =   10.0 MilliJy
localh> IMAGR1: Field   8 min =   -5.9 MilliJy,max =    7.9 MilliJy
localh> IMAGR1: Field   9 min =  -12.6 MilliJy,max =  
.....
--------------------------------------------------------
ocalh> IMAGR1: BGC Clean: using   89 cell beam + residuals >     2.83 MilliJy
localh> IMAGR1:     3208 Residual map points loaded
localh> IMAGR1: Field   11 min algorithm flux=    3.616 MilliJy iter=3510
localh> IMAGR1: Field   11 Clean flux density=    1.355      Jy     3510 comps
localh> IMAGR1: Total Cleaned flux density     =    5.581      Jy   11200 comps
localh> IMAGR1: VISDFT: Begin DFT component subtraction
localh> IMAGR1: I Polarization model processed
------------------------------------------------------------
localh> IMAGR1: Removing     10270 remaining components from initial data
localh> IMAGR1: VISDFT: Begin DFT component subtraction
localh> IMAGR1: I Polarization model processed
-------------------------

This is making it extremely slow (last step of removing ~10000 comp took
15 minutes) on my amd64 2.2GHz machine (~3.2 GHz P-IV). Clearly, FFT is
much faster here.

Thanks.

Subhashis