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<div dir="auto">H for half-precision floats?</div>
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<div dir="auto" style="font-size:14px; color:#909090">Sent from my Verizon, Samsung Galaxy smartphone</div>
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<div>-------- Original message --------</div>
<div>From: peter teuben via fitsbits <fitsbits@listmgr.nrao.edu> </div>
<div>Date: 7/23/25 9:25 AM (GMT-05:00) </div>
<div>To: fitsbits@listmgr.nrao.edu </div>
<div>Cc: peter teuben <teuben@umd.edu> </div>
<div>Subject: Re: [fitsbits] 16-bit floats {External} </div>
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<div class="PlainText">We also need them for BINTABLE, where D and E are for 64 and 32 bit
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floats. Sadly can't expand the alphabet here. F is available, but C is not.<br>
<br>
I guess L is available for 128-bit integer.<br>
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<br>
FITS format code Description 8-bit bytes<br>
<br>
L logical (Boolean) 1<br>
X bit *<br>
B Unsigned byte 1<br>
I 16-bit integer 2<br>
J 32-bit integer 4<br>
K 64-bit integer 8<br>
A character 1<br>
E single precision float (32-bit) 4<br>
D double precision float (64-bit) 8<br>
C single precision complex 8<br>
M double precision complex 16<br>
P array descriptor 8<br>
Q array descriptor 16<br>
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On 7/23/25 08:34, Thomas Robitaille via fitsbits wrote:<br>
> Hi everyone,<br>
><br>
> As far as I understand, IEEE 754-2008 standardized the representation <br>
> of 16-bit floats (as well as 128-bit floats). I was curious whether <br>
> there is any interest in extending the FITS format to allow BITPIX=-16 <br>
> and BITPIX=-128?<br>
><br>
> I am aware of some modern projects that would benefit from having <br>
> 16-bit floats, since they consider it to be sufficient in precision to <br>
> store very large datasets, and using 16-bit floats would perform a lot <br>
> better than using compression on 32-bit floats for example, and 16-bit <br>
> floats would allow a larger dynamic range than using 16-bit ints with <br>
> BSCALE/BZERO.<br>
><br>
> I'm curious to hear if this has been discussed before!<br>
><br>
> Thanks,<br>
> Tom<br>
><br>
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