From lisi.alborghetti at gmail.com  Tue Feb  6 10:06:40 2024
From: lisi.alborghetti at gmail.com (Lisa Alborghetti)
Date: Tue, 6 Feb 2024 16:06:40 +0100
Subject: [AstroPy] Image combination with sigma clipping
Message-ID: <DB96B4E2-270E-4982-9414-EEAF0B56DC05@gmail.com>

Hi everybody,
I?m new to AstroPy, and I have what I believe to be a very simple question: I have a .fits file, containing a series of 50 images that I want to combine to create a dark image of my CCD. Before averaging, I would like to perform a sigma_clipping using mad_std. 
I was trying with something like this:

from astropy import units as u
from astropy.nddata import CCDData
from ccdproc import Combiner
import numpy as np

ccd = CCDData.read('Dark Current/minus_10/5_sec/Background_fits.fits', unit="adu")

combiner = Combiner(ccd)

combiner_clipped = combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median', dev_func='mad_std')

combined_average = combiner_clipped.average_combine()  


But it doesn?t seem to be the right way to do it. In fact, I get:


---> 12 combined_average = combiner_clipped.average_combine()  

AttributeError: 'NoneType' object has no attribute ?average_combine?

Can someone help me with this, please?
Thank you!

Lisa

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From mcraig at mnstate.edu  Tue Feb  6 10:15:49 2024
From: mcraig at mnstate.edu (Craig, Matthew W)
Date: Tue, 6 Feb 2024 15:15:49 +0000
Subject: [AstroPy] Image combination with sigma clipping
In-Reply-To: <DB96B4E2-270E-4982-9414-EEAF0B56DC05@gmail.com>
References: <DB96B4E2-270E-4982-9414-EEAF0B56DC05@gmail.com>
Message-ID: <MW5PR10MB5713738B2E4E96EB6A12A4B0C7462@MW5PR10MB5713.namprd10.prod.outlook.com>

Hi Lisa,

Just to make sure I understand, are the 50 images in different extensions in the same FITS file?

Thanks,

Matt Craig
Schedule: http://physics.mnstate.edu/craig
---
Professor, Department of Physics and Astronomy
MSUM

________________________________
From: AstroPy <astropy-bounces+mcraig=mnstate.edu at python.org> on behalf of Lisa Alborghetti <lisi.alborghetti at gmail.com>
Sent: Tuesday, February 6, 2024 9:06 AM
To: astropy at python.org <astropy at python.org>
Subject: [AstroPy] Image combination with sigma clipping


CAUTION: This e-mail originated from outside the Minnesota State System. Only click links or open attachments from trusted sources. Please report suspicious messages using the "Report Message Button".

Hi everybody,
I?m new to AstroPy, and I have what I believe to be a very simple question: I have a .fits file, containing a series of 50 images that I want to combine to create a dark image of my CCD. Before averaging, I would like to perform a sigma_clipping using mad_std.
I was trying with something like this:

from astropy import units as u
from astropy.nddata import CCDData
from ccdproc import Combiner
import numpy as np

ccd = CCDData.read('Dark Current/minus_10/5_sec/Background_fits.fits', unit="adu")

combiner = Combiner(ccd)

combiner_clipped = combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median', dev_func='mad_std')

combined_average = combiner_clipped.average_combine()


But it doesn?t seem to be the right way to do it. In fact, I get:


---> 12 combined_average = combiner_clipped.average_combine() AttributeError: 'NoneType' object has no attribute ?average_combine?

Can someone help me with this, please?
Thank you!

Lisa

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From lisi.alborghetti at gmail.com  Tue Feb  6 10:25:00 2024
From: lisi.alborghetti at gmail.com (Lisa Alborghetti)
Date: Tue, 6 Feb 2024 16:25:00 +0100
Subject: [AstroPy] Image combination with sigma clipping
In-Reply-To: <MW5PR10MB5713738B2E4E96EB6A12A4B0C7462@MW5PR10MB5713.namprd10.prod.outlook.com>
References: <DB96B4E2-270E-4982-9414-EEAF0B56DC05@gmail.com>
 <MW5PR10MB5713738B2E4E96EB6A12A4B0C7462@MW5PR10MB5713.namprd10.prod.outlook.com>
Message-ID: <B238C9AC-7D5C-4A3E-B992-A025721C4C8F@gmail.com>

Hi Matt, 
Yes, once I have imported the FITS file, I can access each image data by indexing the CCDData object with the extension number.  (ccd[0].data, ccd[16].data etc.)
Thanks, 

Lisa

> On 6 Feb 2024, at 16:15, Craig, Matthew W via AstroPy <astropy at python.org> wrote:
> 
> Hi Lisa,
> 
> Just to make sure I understand, are the 50 images in different extensions in the same FITS file?
> 
> Thanks,
> 
> Matt Craig
> Schedule: http://physics.mnstate.edu/craig
> ---
> Professor, Department of Physics and Astronomy 
> MSUM
> 
> From: AstroPy <astropy-bounces+mcraig=mnstate.edu at python.org <mailto:astropy-bounces+mcraig=mnstate.edu at python.org>> on behalf of Lisa Alborghetti <lisi.alborghetti at gmail.com <mailto:lisi.alborghetti at gmail.com>>
> Sent: Tuesday, February 6, 2024 9:06 AM
> To: astropy at python.org <mailto:astropy at python.org> <astropy at python.org <mailto:astropy at python.org>>
> Subject: [AstroPy] Image combination with sigma clipping
>  
> CAUTION: This e-mail originated from outside the Minnesota State System. Only click links or open attachments from trusted sources. Please report suspicious messages using the "Report Message Button". 
> Hi everybody,
> I?m new to AstroPy, and I have what I believe to be a very simple question: I have a .fits file, containing a series of 50 images that I want to combine to create a dark image of my CCD. Before averaging, I would like to perform a sigma_clipping using mad_std. 
> I was trying with something like this:
> 
> from astropy import units as u
> from astropy.nddata import CCDData
> from ccdproc import Combiner
> import numpy as np
> 
> ccd = CCDData.read('Dark Current/minus_10/5_sec/Background_fits.fits', unit="adu")
> 
> combiner = Combiner(ccd)
> 
> combiner_clipped = combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median', dev_func='mad_std')
> 
> combined_average = combiner_clipped.average_combine()  
> 
> 
> But it doesn?t seem to be the right way to do it. In fact, I get:
> 
> 
> ---> 12
>  combined_average =
> combiner_clipped.average_combine()
> AttributeError:
>  'NoneType' object has no attribute ?average_combine?
> 
> Can someone help me with this, please?
> Thank you!
> 
> Lisa
> 
> _______________________________________________
> AstroPy mailing list
> AstroPy at python.org <mailto:AstroPy at python.org>
> https://mail.python.org/mailman/listinfo/astropy

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From jslavin at cfa.harvard.edu  Tue Feb  6 11:00:52 2024
From: jslavin at cfa.harvard.edu (Slavin, Jonathan)
Date: Tue, 6 Feb 2024 11:00:52 -0500
Subject: [AstroPy] Image combination with sigma clipping
In-Reply-To: <mailman.513.1707233113.3226.astropy@python.org>
References: <mailman.513.1707233113.3226.astropy@python.org>
Message-ID: <CACcRS=fhSx-8TnKd4-pgTC8g=Ye7=Jvh+q7bzJE=734iYmkr1g@mail.gmail.com>

Hi Lisa,

Looks to me like the method sigma_clipping of the Combiner object acts on
the data in place and has no return statement (and so returns None).
If that's true then you want something like:

combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median',
dev_func='mad_std')

combined_average = combiner.average_combine()

Regards,
Jon



> Date: Tue, 6 Feb 2024 16:06:40 +0100
> From: Lisa Alborghetti <lisi.alborghetti at gmail.com>
> To: astropy at python.org
> Subject: [AstroPy] Image combination with sigma clipping
> Message-ID: <DB96B4E2-270E-4982-9414-EEAF0B56DC05 at gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi everybody,
> I?m new to AstroPy, and I have what I believe to be a very simple
> question: I have a .fits file, containing a series of 50 images that I want
> to combine to create a dark image of my CCD. Before averaging, I would like
> to perform a sigma_clipping using mad_std.
> I was trying with something like this:
>
> from astropy import units as u
> from astropy.nddata import CCDData
> from ccdproc import Combiner
> import numpy as np
>
> ccd = CCDData.read('Dark Current/minus_10/5_sec/Background_fits.fits',
> unit="adu")
>
> combiner = Combiner(ccd)
>
> combiner_clipped = combiner.sigma_clipping(low_thresh=2, high_thresh=5,
> func='median', dev_func='mad_std')
>
> combined_average = combiner_clipped.average_combine()
>
>
> But it doesn?t seem to be the right way to do it. In fact, I get:
>
>
> ---> 12 combined_average = combiner_clipped.average_combine()
>
> AttributeError: 'NoneType' object has no attribute ?average_combine?
>
> Can someone help me with this, please?
> Thank you!
>
> Lisa
>
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From lisi.alborghetti at gmail.com  Wed Feb  7 01:33:42 2024
From: lisi.alborghetti at gmail.com (Lisa Alborghetti)
Date: Wed, 7 Feb 2024 07:33:42 +0100
Subject: [AstroPy] Image combination with sigma clipping
In-Reply-To: <CACcRS=fhSx-8TnKd4-pgTC8g=Ye7=Jvh+q7bzJE=734iYmkr1g@mail.gmail.com>
References: <mailman.513.1707233113.3226.astropy@python.org>
 <CACcRS=fhSx-8TnKd4-pgTC8g=Ye7=Jvh+q7bzJE=734iYmkr1g@mail.gmail.com>
Message-ID: <4507BD4A-3FD4-4730-A8A0-5448FE49C3BE@gmail.com>

Yes, I think it works now! 
Thank you very much. 

Lisa 

> On 6 Feb 2024, at 17:00, Slavin, Jonathan via AstroPy <astropy at python.org> wrote:
> 
> Hi Lisa,
> 
> Looks to me like the method sigma_clipping of the Combiner object acts on the data in place and has no return statement (and so returns None).
> If that's true then you want something like:
> 
> combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median', dev_func='mad_std')
> 
> combined_average = combiner.average_combine() 
> 
> Regards,
> Jon
> 
>  
>> Date: Tue, 6 Feb 2024 16:06:40 +0100
>> From: Lisa Alborghetti <lisi.alborghetti at gmail.com <mailto:lisi.alborghetti at gmail.com>>
>> To: astropy at python.org <mailto:astropy at python.org>
>> Subject: [AstroPy] Image combination with sigma clipping
>> Message-ID: <DB96B4E2-270E-4982-9414-EEAF0B56DC05 at gmail.com <mailto:DB96B4E2-270E-4982-9414-EEAF0B56DC05 at gmail.com>>
>> Content-Type: text/plain; charset="utf-8"
>> 
>> Hi everybody,
>> I?m new to AstroPy, and I have what I believe to be a very simple question: I have a .fits file, containing a series of 50 images that I want to combine to create a dark image of my CCD. Before averaging, I would like to perform a sigma_clipping using mad_std. 
>> I was trying with something like this:
>> 
>> from astropy import units as u
>> from astropy.nddata import CCDData
>> from ccdproc import Combiner
>> import numpy as np
>> 
>> ccd = CCDData.read('Dark Current/minus_10/5_sec/Background_fits.fits', unit="adu")
>> 
>> combiner = Combiner(ccd)
>> 
>> combiner_clipped = combiner.sigma_clipping(low_thresh=2, high_thresh=5, func='median', dev_func='mad_std')
>> 
>> combined_average = combiner_clipped.average_combine()  
>> 
>> 
>> But it doesn?t seem to be the right way to do it. In fact, I get:
>> 
>> 
>> ---> 12 combined_average = combiner_clipped.average_combine()  
>> 
>> AttributeError: 'NoneType' object has no attribute ?average_combine?
>> 
>> Can someone help me with this, please?
>> Thank you!
>> 
>> Lisa
> _______________________________________________
> AstroPy mailing list
> AstroPy at python.org
> https://mail.python.org/mailman/listinfo/astropy

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