auto_ownership estimation fails with NL logit model if YAML uses coefficient names

[amsamimi]

ActivitySim in estimation mode crashes when a Nested Logit (NL) model is passed to the auto_ownership module.

When coefficient values are used instead of coefficient names, the code runs successfully. This suggests the issue lies in how the YAML file is being loaded.

This works: NESTS: name: root coefficient: 1 alternatives: - name: NOCAR coefficient: 0.7 alternatives: - cars0 - name: OWNCAR coefficient: 0.6 alternatives: - cars1 - cars2

This does NOT works: NESTS: name: root coefficient: coef_nest_root alternatives: - name: NOCAR coefficient: coef_nest_NOCAR alternatives: - cars0 - name: OWNCAR coefficient: coef_nest_OWNCAR alternatives: - cars1 - cars2

[amsamimi]

@dhensle I created this issue based on the observation we had today. Feel free to add more content if needed.