arr.dtype.kind is 'i' for dtype=unit !?
Hi, What are the possible values of arr.dtype.kind ? It seems that signed and unsigned are considered to be the same "kind"
arr=N.arange(10,dtype=N.uint) arr.dtype.kind 'i' arr.dtype.itemsize 8 (OK - this is just showing off our amd64 linux ;-) )
How can I distinguish signed from unsigned without having to list all possible cases explicitly ? Thanks, Sebastian Haase
Hello all
-----Original Message----- From: numpy-discussion-bounces@lists.sourceforge.net [mailto:numpy- discussion-bounces@lists.sourceforge.net] On Behalf Of Sebastian Haase Sent: 19 September 2006 19:24 To: Discussion of Numerical Python Subject: [Numpy-discussion] arr.dtype.kind is 'i' for dtype=unit !?
Hi, What are the possible values of arr.dtype.kind ?
It seems that signed and unsigned are considered to be the same "kind"
arr=N.arange(10,dtype=N.uint) arr.dtype.kind 'i' arr.dtype.itemsize 8 (OK - this is just showing off our amd64 linux ;-) )
How can I distinguish signed from unsigned without having to list all possible cases explicitly ?
How about sctypes? In [16]: numpy.sctypes.keys() Out[17]: ['int', 'float', 'uint', 'complex', 'others'] So this should work: sometype in numpy.sctypes['uint'] sometype in numpy.sctypes['int'] Cheers, Albert
Sebastian Haase wrote:
Hi, What are the possible values of arr.dtype.kind ?
It seems that signed and unsigned are considered to be the same "kind"
arr=N.arange(10,dtype=N.uint) arr.dtype.kind
'i'
arr.dtype.itemsize
8 (OK - this is just showing off our amd64 linux ;-) )
How can I distinguish signed from unsigned without having to list all possible cases explicitly ?
Hmm.... This is a problem. There is a 'u' kind for unsigned integers. On my system I get 'u' when running the code you just gave. Can anybody on a 64-bit system confirm? -Travis
On Tuesday 19 September 2006 14:46, Travis Oliphant wrote:
Sebastian Haase wrote:
Hi, What are the possible values of arr.dtype.kind ?
It seems that signed and unsigned are considered to be the same "kind"
arr=N.arange(10,dtype=N.uint) arr.dtype.kind
'i'
arr.dtype.itemsize
8 (OK - this is just showing off our amd64 linux ;-) )
How can I distinguish signed from unsigned without having to list all possible cases explicitly ?
Hmm.... This is a problem. There is a 'u' kind for unsigned integers.
On my system I get 'u' when running the code you just gave.
Can anybody on a 64-bit system confirm?
I'm on 64-bit Debian: In [11]: arr=N.arange(10,dtype=N.uint) In [12]: arr.dtype.kind Out[12]: 'u' In [13]: arr.dtype.itemsize Out[13]: 4 In [14]: arr=N.arange(10,dtype=N.long) In [15]: arr.dtype.kind Out[15]: 'i' In [16]: arr.dtype.itemsize Out[16]: 8 Scott -- Scott M. Ransom Address: NRAO Phone: (434) 296-0320 520 Edgemont Rd. email: sransom@nrao.edu Charlottesville, VA 22903 USA GPG Fingerprint: 06A9 9553 78BE 16DB 407B FFCA 9BFA B6FF FFD3 2989
Can anybody on a 64-bit system confirm?
I'm on 64-bit Debian:
In [11]: arr=N.arange(10,dtype=N.uint)
In [12]: arr.dtype.kind Out[12]: 'u'
In [13]: arr.dtype.itemsize Out[13]: 4
In [14]: arr=N.arange(10,dtype=N.long)
In [15]: arr.dtype.kind Out[15]: 'i'
In [16]: arr.dtype.itemsize Out[16]: 8
Ack! That was on the wrong machine (32-bit Debian). Here is the 64-bit version: In [2]: arr=N.arange(10,dtype=N.uint) In [3]: arr.dtype.kind Out[3]: 'u' In [4]: arr.dtype.itemsize Out[4]: 8 In [5]: arr=N.arange(10,dtype=N.long) In [6]: arr.dtype.kind Out[6]: 'i' In [7]: arr.dtype.itemsize Out[7]: 8 Sorry about that, Scott -- Scott M. Ransom Address: NRAO Phone: (434) 296-0320 520 Edgemont Rd. email: sransom@nrao.edu Charlottesville, VA 22903 USA GPG Fingerprint: 06A9 9553 78BE 16DB 407B FFCA 9BFA B6FF FFD3 2989
OK - I'm really sorry !! I also get 'u' -- I had a typo there ... But what is the complete list of kind values ? -Sebastian On Tuesday 19 September 2006 11:54, Scott Ransom wrote:
Can anybody on a 64-bit system confirm?
I'm on 64-bit Debian:
In [11]: arr=N.arange(10,dtype=N.uint)
In [12]: arr.dtype.kind Out[12]: 'u'
In [13]: arr.dtype.itemsize Out[13]: 4
In [14]: arr=N.arange(10,dtype=N.long)
In [15]: arr.dtype.kind Out[15]: 'i'
In [16]: arr.dtype.itemsize Out[16]: 8
Ack! That was on the wrong machine (32-bit Debian). Here is the 64-bit version:
In [2]: arr=N.arange(10,dtype=N.uint)
In [3]: arr.dtype.kind Out[3]: 'u'
In [4]: arr.dtype.itemsize Out[4]: 8
In [5]: arr=N.arange(10,dtype=N.long)
In [6]: arr.dtype.kind Out[6]: 'i'
In [7]: arr.dtype.itemsize Out[7]: 8
Sorry about that,
Scott
Sebastian Haase wrote:
OK - I'm really sorry !! I also get 'u' -- I had a typo there ...
But what is the complete list of kind values ?
It's in the array interface specification: http://numpy.scipy.org/array_interface.shtml -Travis
Hi,
It's in the array interface specification:
I was interested in the 't' (bitfield) type - is there an example of usage somewhere? In [13]: dtype('t8') --------------------------------------------------------------------------- exceptions.TypeError Traceback (most recent call last) /home/mb312/python/<ipython console> TypeError: data type not understood Best, Matthew
Matthew Brett wrote:
Hi,
It's in the array interface specification:
I was interested in the 't' (bitfield) type - is there an example of usage somewhere?
No, It's not implemented in NumPy. It's just part of the array interface specification for completeness. -Travis
participants (6)
-
Albert Strasheim -
Matthew Brett -
Scott Ransom -
Sebastian Haase -
Travis Oliphant -
Travis Oliphant