Usability improvements for correlated field

See merge request !385

Gordian Edenhofer authored Dec 04, 2019 and Philipp Arras committed Dec 04, 2019

Instead of validating the input via `assert`s in user-accessible
functions, raise appropriate errors.

Gordian Edenhofer authored Dec 04, 2019 and Philipp Arras committed Dec 04, 2019

Instead of drawing samples and storing them in a potentially huge list,
draw individual samples only when needed. Hereby, get rid of the
`_stats` function but instead draw samples during computing the
statistics summary.

correlated_field.py: Implement offset in finalize

See merge request !386

Allow for specifying either a Field/MultiField or a float as an offset
for the correlated field during `finalize`.

Small changes in CorrelatedFieldMaker

See merge request !384

Timing helpers

See merge request !379

cosmetics

See merge request !382

Add log1p and expm1 to sugar.py and operator.py

See merge request !381

Amend the operator section as well to make both functions also work on
chains of operators.

Renaming

See merge request !378

Correlated Field model for DomainTuple

See merge request !373