From time to time, we will wish to select a specific constituent of an array. We will take a look at how to do this, but to kick off, let's make a 2 x 2 matrix again (see the `elementselection.py`

file in this book's code bundle):

In: a = array([[1,2],[3,4]]) In: a Out: array([[1, 2], [3, 4]])

The matrix was made this time by giving the `array()`

function a list of lists. We will now choose each item of the matrix one at a time, as shown in the following code snippet. Recall that the index numbers begin from `0`

:

In: a[0,0] Out: 1 In: a[0,1] Out: 2 In: a[1,0] Out: 3 In: a[1,1] Out: 4

As you can see, choosing elements of an array is fairly simple. For the array `a`

, we just employ the notation `a[m,n]`

, where `m`

and `n`

are the indices ...

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