Oh.  My mistake. I thought I had an array of 2 objects which were ints.  I actually had an array of one list of 2 ints.  It works properly if I construct the array properly.
 

In [14]: a = numpy.empty((2), dtype=object)

In [15]: a[0:]=[2,3]

In [16]: a
Out[16]: array([2, 3], dtype=object)

In [17]: a.shape
Out[17]: (2,)

In [18]: a[0]
Out[18]: 2

In [19]: a[1]
Out[19]: 3

In [20]: numpy.argmax(a)
Out[20]: 1

 

 


 
On 10/29/06, Charles R Harris <[EMAIL PROTECTED]> wrote:


On 10/29/06, Tom Denniston < [EMAIL PROTECTED]> wrote:
I recently upgraded to numpy 1.0 from 1.0b5.   I noticed that numpy.argmax behavior is very strange on object arrays.  See below:
 
(Pdb) numpy.__version__
'1.0'
(Pdb) numpy.argmax(numpy.array([2, 3], dtype=object))
0
(Pdb) numpy.argmax(numpy.array([2, 3], dtype=int))
1
(Pdb) numpy.argmax(numpy.array([2, 3], dtype=object), axis=0)
0
 
 
I would expect the argmax to behave the same on the dtype=int and dtype=object examples but it doesn't.  Am I missing some subtelty or is this just a bug?  1.0 is the most recent version, right?

Suppose

In [22]: array([1,[2,3]], dtype=object)
Out[22]: array([1, [2, 3]], dtype=object)

How would you compare the elements?

In [27]: 2 < [0,0]
Out[27]: True

In [28]: [0,0] > 2
Out[28]: True

Compares memory locations?

In [28]: [2] < [0,0]
Out[28]: False

Lexical ordering?

 
I don't know how python interprets these things. That said, I suspect your example should behave better, but it might give strange results sometimes anyway.

Chuck
 


-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642

_______________________________________________
Numpy-discussion mailing list
Numpy-discussion@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/numpy-discussion



-------------------------------------------------------------------------
Using Tomcat but need to do more? Need to support web services, security?
Get stuff done quickly with pre-integrated technology to make your job easier
Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
_______________________________________________
Numpy-discussion mailing list
Numpy-discussion@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/numpy-discussion

Reply via email to