Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-10 Thread frank wang
On my two systems with Intel Core2 DUO, finfo(float128) gives me the nameerro, NameError: name 'float128' is not defined. Why? Thanks Frank Date: Tue, 9 Dec 2008 21:10:32 -0600 From: [EMAIL PROTECTED] To: numpy-discussion@scipy.org Subject: Re: [Numpy-discussion] Importance of order when

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-10 Thread Charles R Harris
On Wed, Dec 10, 2008 at 11:00 AM, frank wang [EMAIL PROTECTED] wrote: On my two systems with Intel Core2 DUO, finfo(float128) gives me the nameerro, NameError: name 'float128' is not defined. Why? You probably run a 32 bit OS. IEEE extended precision is 80 bits. On 32 bit systems it fits in

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-10 Thread Robert Kern
On Wed, Dec 10, 2008 at 12:07, Charles R Harris [EMAIL PROTECTED] wrote: On Wed, Dec 10, 2008 at 11:00 AM, frank wang [EMAIL PROTECTED] wrote: On my two systems with Intel Core2 DUO, finfo(float128) gives me the nameerro, NameError: name 'float128' is not defined. Why? You probably run a

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-10 Thread Charles R Harris
On Wed, Dec 10, 2008 at 11:58 AM, Robert Kern [EMAIL PROTECTED] wrote: On Wed, Dec 10, 2008 at 12:07, Charles R Harris [EMAIL PROTECTED] wrote: On Wed, Dec 10, 2008 at 11:00 AM, frank wang [EMAIL PROTECTED] wrote: On my two systems with Intel Core2 DUO, finfo(float128) gives me the

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-10 Thread Charles R Harris
On Wed, Dec 10, 2008 at 11:58 AM, Robert Kern [EMAIL PROTECTED] wrote: On Wed, Dec 10, 2008 at 12:07, Charles R Harris [EMAIL PROTECTED] wrote: On Wed, Dec 10, 2008 at 11:00 AM, frank wang [EMAIL PROTECTED] wrote: On my two systems with Intel Core2 DUO, finfo(float128) gives me the

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Nadav Horesh
of Numerical Python נושא: [Numpy-discussion] Importance of order when summing values in anarray Hi All, I have encountered a puzzling issue and I am not certain if this is a mistake of my own doing or not. Would someone kindly just look over this issue to make sure I'm not doing something very silly

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Hanni Ali
] בשם Hanni Ali נשלח: ג 09-דצמבר-08 16:07 אל: Discussion of Numerical Python נושא: [Numpy-discussion] Importance of order when summing values in anarray Hi All, I have encountered a puzzling issue and I am not certain if this is a mistake of my own doing or not. Would someone kindly just

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Bruce Southey
16:07 אל: Discussion of Numerical Python נושא: [Numpy-discussion] Importance of order when summing values in anarray Hi All, I have encountered a puzzling issue and I am not certain if this is a mistake of my own doing or not. Would someone kindly just look over this issue to make sure

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Hanni Ali
Hi Bruce, Ahh, but I would have thought the precision for the array operation would be the same no matter which values I wish to sum? The array is in float64 in all cases. I would not have thought altering the type of the integer values would make any difference as these indices are all below 5

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Bruce Southey
Hanni Ali wrote: Hi Bruce, Ahh, but I would have thought the precision for the array operation would be the same no matter which values I wish to sum? The array is in float64 in all cases. I would not have thought altering the type of the integer values would make any difference as

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Robert Kern
On Tue, Dec 9, 2008 at 09:51, Nadav Horesh [EMAIL PROTECTED] wrote: As much as I know float128 are in fact 80 bits (64 mantissa + 16 exponent) so the precision is 18-19 digits (not 34) float128 should be 128 bits wide. If it's not on your platform, please let us know as that is a bug in your

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Charles R Harris
On Tue, Dec 9, 2008 at 1:40 PM, Robert Kern [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 09:51, Nadav Horesh [EMAIL PROTECTED] wrote: As much as I know float128 are in fact 80 bits (64 mantissa + 16 exponent) so the precision is 18-19 digits (not 34) float128 should be 128 bits wide. If

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Robert Kern
On Tue, Dec 9, 2008 at 21:01, Charles R Harris [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 1:40 PM, Robert Kern [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 09:51, Nadav Horesh [EMAIL PROTECTED] wrote: As much as I know float128 are in fact 80 bits (64 mantissa + 16 exponent) so

Re: [Numpy-discussion] Importance of order when summing values in anarray

2008-12-09 Thread Charles R Harris
On Tue, Dec 9, 2008 at 8:10 PM, Robert Kern [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 21:01, Charles R Harris [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 1:40 PM, Robert Kern [EMAIL PROTECTED] wrote: On Tue, Dec 9, 2008 at 09:51, Nadav Horesh [EMAIL PROTECTED] wrote: As