| 28 Jul 2021 |
|  Satoru Katsuda set a profile picture. | 02:43:35 |
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| 29 Jul 2021 |
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 eblur | Dear all, the Astropy Project is preparing for AAS 239 (Salt Lake City, Jan 9-13)!
We are looking for:
(1) Astropy Workshop Facilitators - if you would like to be an instructor for a portion of the Astropy Workshop content, please respond to this message. We welcome modifications or additions to the current content, or you can lead it as-is. Some funding is available to support you attending the conference in order to lead the workshop, but we can’t guarantee it for a large number of people. Please indicate whether or not you will need Astropy support to participate. Note that the workshops take place 1-2 days before the main conference.
(2) Astropy Booth Coordinator - In the past, the Astropy Project has sponsored a booth in the AAS Exhibit Hall, highlighting Astropy, Astropy affiliated, and NumFocus sponsored projects. We are looking for someone to be the on-site booth lead. This includes managing the booth schedule and staffing, booth set-up, and clean up. The past lead (Lia, eblur) will assist in this process and provide template flyer and poster materials. The booth coordinator will have their registration covered. Please indicate whether travel support is needed, as well.
Please email, DM in Slack, or reply to this thread if you are interested! | 18:10:10 |
|  muondude joined the room. | 22:24:08 |
| muondude changed their display name from slack_astropy_U029NDTU70T to Samuel Gasster. | 22:26:14 |
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| muondude changed their profile picture. | 22:44:31 |
| muondude | Hello: My first time on Astropy Slack. I'm a Physicist working on a Python model for earth remote sensing. I'm using the Blackbody function and want to convert the radiance from "cgs unit" to SI units. I googled a bit, looked at some of the manual but nothing I've tried works. I would like to change from the default "erg/Hz/s/cm2/sr" to "W/m2/micron/sr". Here is a code snippet: bb = BlackBody(temperature=temperature)
bb_result = bb(lam) ; I tried various .to() but I get this error: "_UnitConversionError: 'erg / (cm2 Hz s sr)' and 'J / (m2 micron s sr)' are not convertible_". Any help would be appreciated. (apologies if this is the wrong channel). -- Sam | 22:48:59 |
| muondude | (edited) ... to "W/m2/micron/sr". => ... to "W/m2/micron/sr". Here is a code snippet: `bb = BlackBody(temperature=temperature)`
bb_result = bb(lam) | 22:49:53 |
| muondude | (edited) ... BlackBody(temperature=temperature)`
bb_result = bb(lam) => ... BlackBody(temperature=temperature)`
`bb_result = bb(lam) ;` I tried various .to() but I get this error: "_UnitConversionError: 'erg / (cm2 Hz s sr)' and 'J / (m2 micron s sr)' are not convertible_". Any help would be appreciated. (apologies if this is the wrong channel). -- Sam | 22:51:42 |
| 30 Jul 2021 |
 pllim | In reply to@slack_astropy_U029NDTU70T:openastronomy.org
Hello: My first time on Astropy Slack. I'm a Physicist working on a Python model for earth remote sensing. I'm using the Blackbody function and want to convert the radiance from "cgs unit" to SI units. I googled a bit, looked at some of the manual but nothing I've tried works. I would like to change from the default "erg/Hz/s/cm2/sr" to "W/m2/micron/sr". Here is a code snippet: bb = BlackBody(temperature=temperature)
bb_result = bb(lam) ; I tried various .to() but I get this error: "_UnitConversionError: 'erg / (cm2 Hz s sr)' and 'J / (m2 micron s sr)' are not convertible_". Any help would be appreciated. (apologies if this is the wrong channel). -- Sam There is a #astropy_modeling:openastronomy.org channel too. Karl Gordon might know. | 00:03:01 |
 Derek Homeier | In reply toundefined
You can convert to _B_nu_ in SI units simply as bb(lam).to('W / (m2 Hz sr)', but the conversion to _B_lambda_ is wavelength/frequency-dependent and thus requires that information. You can specify it using the spectral_density equivalency:
bb(lam).to('W / (m2 micron sr)', equivalencies=u.spectral_density(lam) | 00:19:33 |
| Derek Homeier | In reply toundefined
(edited) ... to _F_nu_ in SI units simply as `bb(lam).to('W / (m2 Hz sr)'`, but the conversion to _F_lambda_ is ... => ... to _B_nu_ in SI units simply as `bb(lam).to('W / (m2 Hz sr)'`, but the conversion to _B_lambda_ is ... | 00:24:31 |
| muondude | In reply to@slack_astropy_UK6RZ6C3S:openastronomy.org
You can convert to _B_nu_ in SI units simply as bb(lam).to('W / (m2 Hz sr)', but the conversion to _B_lambda_ is wavelength/frequency-dependent and thus requires that information. You can specify it using the spectral_density equivalency:
bb(lam).to('W / (m2 micron sr)', equivalencies=u.spectral_density(lam) Derek: That did the trick! Thanks for the quick (and correct ;-)) replay. Cheers — Sam | 01:51:36 |
| 31 Jul 2021 |
| muondude changed their display name from Samuel Gasster to muondude. | 05:18:49 |
| 3 Aug 2021 |
|  James Tocknell joined the room. | 05:35:03 |
| James Tocknell | Hi all. Is there some way to get wcslib to print its errors out? I'm getting ValueError: Internal error in wcslib header parser when trying to read a header (it uses the ZPX projection if that rings any bells), so I'm trying to get more information about why its erroring. | 05:38:35 |
 maxnoe | Leap Seconds: Causing Bugs Even When They Don't Happen - https://berthub.eu/articles/posts/leapseconds-expose-bugs-even-when-they-dont-happen/ | 11:16:37 |
| pllim | In reply to@slack_astropy_U011S3S5NUQ:openastronomy.org
Hi all. Is there some way to get wcslib to print its errors out? I'm getting ValueError: Internal error in wcslib header parser when trying to read a header (it uses the ZPX projection if that rings any bells), so I'm trying to get more information about why its erroring. FWIW, that error is from https://github.com/astropy/astropy/blob/df3e5bb36120797065c8e326309663ab1a3df788/astropy/wcs/src/pyutil.c#L347 | 12:25:44 |
| Derek Homeier | In reply to@slack_astropy_U774ARTKR:openastronomy.org
FWIW, that error is from https://github.com/astropy/astropy/blob/df3e5bb36120797065c8e326309663ab1a3df788/astropy/wcs/src/pyutil.c#L347 And that could point to any of 6 or 7 exceptions in https://github.com/astropy/astropy/blob/df3e5bb36120797065c8e326309663ab1a3df788/cextern/wcslib/C/flexed/wcspih.c ;
does not look like there are any debugging options implemented. | 17:36:02 |
| pllim | In reply to@slack_astropy_UK6RZ6C3S:openastronomy.org
And that could point to any of 6 or 7 exceptions in https://github.com/astropy/astropy/blob/df3e5bb36120797065c8e326309663ab1a3df788/cextern/wcslib/C/flexed/wcspih.c ;
does not look like there are any debugging options implemented. Can't go wrong with some good ol' printf... 😂 | 17:37:36 |
| 4 Aug 2021 |
| James Tocknell | In reply to@slack_astropy_U774ARTKR:openastronomy.org
Can't go wrong with some good ol' printf... 😂 Ah, so there's no option to switch on some additional debugging output? I'll see if I can some up with something, and send a PR maybe. | 01:53:21 |
| Derek Homeier | In reply to@slack_astropy_U011S3S5NUQ:openastronomy.org
Ah, so there's no option to switch on some additional debugging output? I'll see if I can some up with something, and send a PR maybe. For the WCSLIB sources it’s a bit complicated since we are trying to keep them in sync with upstream as far as possible. But maybe enabling a debug build could be an option; having those exceptions print out the current card seems reasonable enough. | 11:53:38 |
| Derek Homeier | In reply to@slack_astropy_UK6RZ6C3S:openastronomy.org
For the WCSLIB sources it’s a bit complicated since we are trying to keep them in sync with upstream as far as possible. But maybe enabling a debug build could be an option; having those exceptions print out the current card seems reasonable enough. In fact all but one of them are triggered on failing to read an expected either SPC or " in one of the WAT* cards, if that rings any bells.
But the remaining one on
yyextra-abort_jmp_env>
might be a bit harder to track down. | 12:05:54 |
| pllim | In reply to@slack_astropy_UK6RZ6C3S:openastronomy.org
In fact all but one of them are triggered on failing to read an expected either SPC or " in one of the WAT* cards, if that rings any bells.
But the remaining one on
yyextra-abort_jmp_env>
might be a bit harder to track down. Yeah, if your patch needs to touch anything in extern or cextern, might as well submit it upstream. | 15:19:58 |
| Derek Homeier | In reply to@slack_astropy_U774ARTKR:openastronomy.org
Yeah, if your patch needs to touch anything in extern or cextern, might as well submit it upstream. which in this case means “send a mail to Mark Calabretta”. :robot-winking: | 15:45:49 |
