Fra - 5 months ago 75

Python Question

I have a pandas Dataframe with N columns representing the coordinates of a vector (for example X, Y, Z, but could be more than 3D).

I would like to aggregate the dataframe along the rows with an arbitrary function that combines the columns, for example the norm:

`(X^2 + Y^2 + Y^2)`

I want to do something similar to what is done here and here and here but I want to keep it general enough that the number of columns can change and it behaves like

`DataFrame.mean(axis = 1)`

or

`DataFrame.sum(axis = 1)`

Answer

I found a faster solution than what @elyase suggested:

```
np.sqrt(np.square(df).sum(axis=1))
```