Nick T - 6 months ago 186

Python Question

Is there a baked-in Numpy/Scipy function to find the interquartile range? I can do it pretty easily myself, but

`mean()`

`sum/len`

`def IQR(dist):`

return np.percentile(dist, 75) - np.percentile(dist, 25)

Answer

`np.percentile`

takes multiple percentile arguments, and you are slightly better off doing:

```
q75, q25 = np.percentile(x, [75 ,25])
iqr = q75 - q25
```

or

```
iqr = np.subtract(*np.percentile(x, [75, 25]))
```

than making two calls to `percentile`

:

```
In [8]: x = np.random.rand(1e6)
In [9]: %timeit q75, q25 = np.percentile(x, [75 ,25]); iqr = q75 - q25
10 loops, best of 3: 24.2 ms per loop
In [10]: %timeit iqr = np.subtract(*np.percentile(x, [75, 25]))
10 loops, best of 3: 24.2 ms per loop
In [11]: %timeit iqr = np.percentile(x, 75) - np.percentile(x, 25)
10 loops, best of 3: 33.7 ms per loop
```