Re: [Numpy-discussion] float128 in fact float80

Hi, On Sun, Oct 16, 2011 at 6:22 PM, Charles R Harris wrote: > > > On Sun, Oct 16, 2011 at 6:13 PM, Nathaniel Smith wrote: >> >> On Sun, Oct 16, 2011 at 4:29 PM, Charles R Harris >> wrote: >> > On Sun, Oct 16, 2011 at 4:16 PM, Nathaniel Smith wrote: >> >> I understand the argument that you don

Re: [Numpy-discussion] float128 in fact float80

On Mon, Oct 17, 2011 at 2:20 AM, Dag Sverre Seljebotn < d.s.seljeb...@astro.uio.no> wrote: > On 10/17/2011 03:22 AM, Charles R Harris wrote: > > > > > > On Sun, Oct 16, 2011 at 6:13 PM, Nathaniel Smith > > wrote: > > > > The solution is just to call it 'longdouble', whi

Re: [Numpy-discussion] float128 in fact float80

On 10/17/2011 03:22 AM, Charles R Harris wrote: > > > On Sun, Oct 16, 2011 at 6:13 PM, Nathaniel Smith > wrote: > > The solution is just to call it 'longdouble', which clearly > communicates 'this does some quirky thing that depends on your C > compiler and archi

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 6:13 PM, Nathaniel Smith wrote: > On Sun, Oct 16, 2011 at 4:29 PM, Charles R Harris > wrote: > > On Sun, Oct 16, 2011 at 4:16 PM, Nathaniel Smith wrote: > >> I understand the argument that you don't want to call it "float80" > >> because not all machines support a float8

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 4:29 PM, Charles R Harris wrote: > On Sun, Oct 16, 2011 at 4:16 PM, Nathaniel Smith wrote: >> I understand the argument that you don't want to call it "float80" >> because not all machines support a float80 type. But I don't >> understand why we would solve that problem by

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 4:16 PM, Nathaniel Smith wrote: > On Sun, Oct 16, 2011 at 3:04 PM, Matthew Brett > wrote: > > If we agree that float128 is a bad name for something that isn't IEEE > > binary128, and there is already a longdouble type (thanks for pointing > > that out), then what about: >

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 3:04 PM, Matthew Brett wrote: > If we agree that float128 is a bad name for something that isn't IEEE > binary128, and there is already a longdouble type (thanks for pointing > that out), then what about: > > Deprecating float128 / float96 as names > Preferring longdouble f

Re: [Numpy-discussion] float128 in fact float80

Hi, On Sun, Oct 16, 2011 at 2:11 PM, David Cournapeau wrote: > On Sun, Oct 16, 2011 at 7:40 PM, Matthew Brett > wrote: >> Hi, > >> If we use float64 we know what that is.  If we are using float128, >> we've got no idea what it is. > > I think there is no arguing here: the ideal solution would b

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 7:40 PM, Matthew Brett wrote: > Hi, > If we use float64 we know what that is.  If we are using float128, > we've got no idea what it is. I think there is no arguing here: the ideal solution would be to follow what happens with 32 and 64 bits reprensentations. But this is

Re: [Numpy-discussion] float128 in fact float80

Hi, On Sun, Oct 16, 2011 at 11:40 AM, Matthew Brett wrote: > Hi, > > On Sun, Oct 16, 2011 at 1:18 AM, David Cournapeau wrote: >> On Sun, Oct 16, 2011 at 8:33 AM, Matthew Brett >> wrote: >>> Hi, >>> >>> On Sun, Oct 16, 2011 at 12:28 AM, David Cournapeau >>> wrote: On Sun, Oct 16, 2011 at

Re: [Numpy-discussion] float128 in fact float80

Hi, On Sun, Oct 16, 2011 at 1:18 AM, David Cournapeau wrote: > On Sun, Oct 16, 2011 at 8:33 AM, Matthew Brett > wrote: >> Hi, >> >> On Sun, Oct 16, 2011 at 12:28 AM, David Cournapeau >> wrote: >>> On Sun, Oct 16, 2011 at 8:04 AM, Matthew Brett >>> wrote: Hi, On Sat, Oct 15, 2

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 8:33 AM, Matthew Brett wrote: > Hi, > > On Sun, Oct 16, 2011 at 12:28 AM, David Cournapeau wrote: >> On Sun, Oct 16, 2011 at 8:04 AM, Matthew Brett >> wrote: >>> Hi, >>> >>> On Sat, Oct 15, 2011 at 11:04 PM, Nadav Horesh >>> wrote: On 32 bit systems it consumes 96

Re: [Numpy-discussion] float128 in fact float80

Hi, On Sun, Oct 16, 2011 at 12:28 AM, David Cournapeau wrote: > On Sun, Oct 16, 2011 at 8:04 AM, Matthew Brett > wrote: >> Hi, >> >> On Sat, Oct 15, 2011 at 11:04 PM, Nadav Horesh >> wrote: >>> On 32 bit systems it consumes 96 bits (3 x 32). and hence float96 >>> On 64 bit machines it consume

Re: [Numpy-discussion] float128 in fact float80

On Sun, Oct 16, 2011 at 8:04 AM, Matthew Brett wrote: > Hi, > > On Sat, Oct 15, 2011 at 11:04 PM, Nadav Horesh wrote: >> On 32 bit systems it consumes 96 bits (3 x 32). and hence float96 >> On 64 bit machines it consumes 128 bits (2x64). >> The variable size is set for an efficient addressing, wh

Re: [Numpy-discussion] float128 in fact float80

Hi, On Sat, Oct 15, 2011 at 11:04 PM, Nadav Horesh wrote: > On 32 bit systems it consumes 96 bits (3 x 32). and hence float96 > On 64 bit machines it consumes 128 bits (2x64). > The variable size is set for an efficient addressing, while the calculation > in hardware is carried in the 80 bits FP

Re: [Numpy-discussion] float128 in fact float80

From: numpy-discussion-boun...@scipy.org [numpy-discussion-boun...@scipy.org] On Behalf Of Matthew Brett [matthew.br...@gmail.com] Sent: 16 October 2011 01:29 To: Discussion of Numerical Python Subject: [Numpy-discussion] float128 in fact float80 Hi, After getting rather confused, I concluded

[Numpy-discussion] float128 in fact float80

Hi, After getting rather confused, I concluded that float128 on a couple of Intel systems I have, is in fact an 80 bit extended precision number: http://en.wikipedia.org/wiki/Extended_precision >>> np.finfo(np.float128).nmant 63 >>> np.finfo(np.float128).nexp 15 That is rather confusing. What