var

var(fs)

Computes the point-wise variance in fs.

Parameters

fs (Fieldset) – input fieldset

Return type

Fieldset

The output is a Fieldset with one field only. A missing value in any field in fs will result in a missing value in the corresponding grid point in the output fieldset.

With n fields in fs by denoting the i-th value in the k-th field by \(x_{i}^{k}\) the output values can be written as:

\[v_{i} = \frac {1}{n} \sum_{k}^{n} (x_{i}^{k})^2 - (\frac {1}{n} \sum_{k}^{n} x_{i}^{k})^2\]

Note

The following lines are equivalent:

y = mv.var(x)
y = mv.mean(x*x)-mv.mean(x)**2