Fix #47

Fix #46

There is often not enough data for 2d interpolation at intermediate data
analysis steps

Fix #41

Fix #44

Fix #43

Fix #45

For #45

For #45

For #44

For #44

For #43

Fix #42

For #42

For #41

For #41

For #41

For #41

Needed for two-dimensional Gaussian model

For #41