How do i compute with (numpy) -arrays eloquently in python

Question

How can i express this construct in a more efficient way?

x = [2, 4, 6, 8, 10]
for p in x:
   x = x/2
print x

there has to be a good way to do this.

Your code will raise a TypeError. I am not sure what you are trying to achieve, can you try rephrasing the question or providing a valid code example? — Chris
– Chris, Commented May 24, 2012 at 15:35
hi maybe you express has some error, x=x/2, how a list can divide by a integer — lioncin
– lioncin, Commented May 24, 2012 at 15:37

NPE · Accepted Answer · 2012-05-24 15:34:51Z

3

If you are trying to divide every element of x by 2, then the following will do it:

x = np.array([2, 4, 6, 8, 10])
x /= 2

The resulting value of x is array([1, 2, 3, 4, 5]).

Note that the above uses integer (truncating) division. If you want floating-point division, either make x into a floating-point array:

x = np.array([2, 4, 6, 8, 10], dtype='float64')

or change the division to:

x = x / 2.0

answered May 24, 2012 at 15:34

NPE

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Comments

Adobe · Accepted Answer · 2012-05-24 15:34:41Z

0

If it is a numpy array You can do it all at once:

In [4]: from numpy import array

In [5]: x = array([2, 4, 6, 8, 10])

In [6]: print x/2
[1 2 3 4 5]

answered May 24, 2012 at 15:34

Adobe

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