user3601754 - 11 months ago 111

Python Question

I would like to obtain the slopes of the linear regression of my data, but the Y contains some nan values...thus it perturbs linregress function...

For example :

`from scipy import stats`

import numpy as np

X = np.array([0,1,2,3,4,5])

Y = np.array([np.NaN,4, 5, 10, 2, 5])

stats.linregress(X,Y)

But, I obtain : (nan, nan, nan, nan, nan)

Thus i try to mask invalid values as you can see:

`import numpy.ma as ma`

stats.linregress((X),ma.masked_invalid(Y))

But it s the same...I dont see what i have to do...

Answer

Try the following:

```
Y=Y[np.logical_not(np.isnan(Y))]
X=X[np.logical_not(np.isnan(Y))]
```

upd: as Warren noticed, `Y`

will be updated, so the `nans`

are gone. You can feed `Y[np.logical_not(np.isnan(Y))]`

and ```
X=X[np.logical_not(np.isnan(Y))]
```

directly into linear regression. Or see Warren's answer with `np.isfinite`

Source (Stackoverflow)