Quick numpy array extension
<p>I wonder if there is a trick to extending a numpy array with consecutive
numbers in between each original values, up to a user controlled default length. Perhaps there is already a built-in function that turns x into y</p>

<pre><code>x=np.array([4,8,4,10])

y=np.array([4,5,6,7,8,9,10,11,4,5,6,7,10,11,12,13])
</code></pre>

<p>Here the length between each element that I added was three. Speed is of the essence here. I need something like this for my column data to work in creating a sparse
matrix.</p>

<p>Also, if I have an array such as </p>

<pre><code>s=np.array([0,1])
</code></pre>

<p>is there a quick way to extend each element an arbitrary amount of
times, lets say 4 for example:</p>

<pre><code>s=np.array([0,0,0,0,1,1,1,1])
</code></pre>

<p>This works on lists:</p>

<pre><code>def extend(myList, n):
    extensions = [range(x, x + n) for x in myList]
    return [item for sublist in extensions for item in sublist] # flatten
</code></pre>

<p>Use as follows:</p>

<pre><code>extend([4, 8, 4, 10], 4)
</code></pre>

python arrays numpy