[daip] IRING question

[Leonia Kogan]

Hi Glen,

You wrote:
 >After setting the inner, outer radius (using only one ring in the   
example below) I find that the number of points making >up the  area  
under analysis varies.

If the number varies when you repeat IRING with the same inputs, it is 
strange

So you have pixel = 0.5"
     you have outerradius = 0.8"= 1.6 pixels

The four inner points (pixels) are definetly inside of your inner radius 
circle.
The distance to the 8 outer  pixel centers is sqrt(0.5^2 + 1.5^2)  = 
1.58 cells

1.58 is almoust equl to 1.6=outerradius

So someting strange can be expected here because of the rounding problem.

I do not think the fix of IRING is required here.



Leonia


Glenn Morrison wrote:

> Hi Leonia,
>
> 0.5" is the pixel size.
>
> -Thanks
>
> --Glenn
>
> On Jun 29, 2006, at 7:23 AM, Leonia Kogan wrote:
>
>> Hi Glen,
>>
>> What is the cell size at the image?
>>
>> Leonia
>>
>> Glenn Morrison wrote:
>>
>>> Hi Eric,
>>>
>>> I'm using IRING and found a bit of odd behavior.
>>>
>>> After setting the inner, outer radius (using only one ring in the   
>>> example below) I find that the number of points making up the  area  
>>> under analysis varies. For the example below with an inner  
>>> radius=0  and outer=0.8", the area in pixels varies between 7-9  
>>> pixels. Why  does this happen?
>>>
>>> --Thanks
>>>
>>> --Glenn
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> IRING1: Task IRING  (release of 31DEC05) begins
>>> AIPS 1: Resumes
>>> IRING1: Ring  Inner  Outer  Points    Average     Sigma     Cumul.  
>>> Flux
>>> IRING1:          (arcsec)             (JY/BEAM )  (JY/BEAM )  
>>> (JY      )
>>> IRING1:   1      .0     .8       8     .1741E-05   .1456E-05   . 
>>> 1173E-05
>>> IRING1: Appears to have ended successfully
>>> IRING1: localhost    31DEC05 TST: Cpu=       1.4  Real=       2
>>> AIPS 1: Task IRING   has finished
>>> IRING1: Task IRING  (release of 31DEC05) begins
>>> AIPS 1: Resumes
>>> IRING1: Ring  Inner  Outer  Points    Average     Sigma     Cumul.  
>>> Flux
>>> IRING1:          (arcsec)             (JY/BEAM )  (JY/BEAM )  
>>> (JY      )
>>> IRING1:   1      .0     .8       7     .2870E-05   .2829E-05   . 
>>> 1692E-05
>>> IRING1: Appears to have ended successfully
>>> IRING1: localhost    31DEC05 TST: Cpu=       1.4  Real=       2
>>> AIPS 1: Task IRING   has finished
>>> IRING1: Task IRING  (release of 31DEC05) begins
>>> AIPS 1: Resumes
>>> IRING1: Ring  Inner  Outer  Points    Average     Sigma     Cumul.  
>>> Flux
>>> IRING1:          (arcsec)             (JY/BEAM )  (JY/BEAM )  
>>> (JY      )
>>> IRING1:   1      .0     .8       8     .6965E-06   .2362E-05   . 
>>> 4694E-06
>>> IRING1: Appears to have ended successfully
>>> IRING1: localhost    31DEC05 TST: Cpu=       1.4  Real=       2
>>> AIPS 1: Task IRING   has finished
>>> IRING1: Task IRING  (release of 31DEC05) begins
>>> AIPS 1: Resumes
>>> IRING1: Ring  Inner  Outer  Points    Average     Sigma     Cumul.  
>>> Flux
>>> IRING1:          (arcsec)             (JY/BEAM )  (JY/BEAM )  
>>> (JY      )
>>> IRING1:   1      .0     .8       9    -.2418E-05   .4635E-05  -. 
>>> 1833E-05
>>> IRING1: Appears to have ended successfully
>>> IRING1: localhost    31DEC05 TST: Cpu=       1.4  Real=       2
>>> AIPS 1: Task IRING   has finished
>>>
>>>
>>>
>>>
>>>
>>>
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>>>
>>