indexing arrays

[John [H2O]]

I'm having trouble slicing arrays:

I thought I could do the following:

>>i = array(range(140 ,149))
>>j = array(range(5,2 0))
>>a = acc[i,j]

Traceback (most recent call last):
File "<string>", line 1, in <string>
ValueError: shape mismatch: objects cannot be broadcast to a single shape

It's strange, because I can do this:

>>a = acc[140:148,5:19]
>>>

Anyone know what I am doing wrong?

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[Emily Rodgers]

Re: indexing arrays


"John [H2O]" <washakie@gmail .comwrote in message
news:mailman.23 21.1223644314.3 487.python-list@python.org ...

>
I'm having trouble slicing arrays:
>
I thought I could do the following:

>>>i = array(range(140 ,149))
>>>j = array(range(5,2 0))
>>>a = acc[i,j]

Traceback (most recent call last):
File "<string>", line 1, in <string>
ValueError: shape mismatch: objects cannot be broadcast to a single shape
>
It's strange, because I can do this:
>

>>>a = acc[140:148,5:19]
>>>>

>
>
Anyone know what I am doing wrong?

What data structure is acc, and what are you trying to do?

[Jeremy Sanders]

Re: indexing arrays

John [H2O] wrote:

Anyone know what I am doing wrong?

The arrays in the numpy package are more sophisticated than the built-in
array package. This sort of thing works there:

>>import numpy
>>a = numpy.array([1,2,3,4,5,6,7,8])*2
>>a

array([ 2, 4, 6, 8, 10, 12, 14, 16])

>>a[range(3,6)]

array([ 8, 10, 12])

Jeremy

--
Jeremy Sanders

http://www.jeremysanders.net/