CFA and SEM with PyMC (#698)

* First commit CFA and SEM

Signed-off-by: Nathaniel <[email protected]>

* test pre-commit hooks

Signed-off-by: Nathaniel <[email protected]>

* updated for pre-commit

Signed-off-by: Nathaniel <[email protected]>

* updated git index

Signed-off-by: Nathaniel <[email protected]>

* update with full run

Signed-off-by: Nathaniel <[email protected]>

* add some text write up and a pair plot

Signed-off-by: Nathaniel <[email protected]>

* update with full run and text

Signed-off-by: Nathaniel <[email protected]>

* Run with explained variance calculations

Signed-off-by: Nathaniel <[email protected]>

* Add sem structure section

Signed-off-by: Nathaniel <[email protected]>

* full run with lavaan syntax noted

Signed-off-by: Nathaniel <[email protected]>

* update with draft conclusion

Signed-off-by: Nathaniel <[email protected]>

* tigher writing

Signed-off-by: Nathaniel <[email protected]>

* tidying

Signed-off-by: Nathaniel <[email protected]>

* emphasis on exchangeability

Signed-off-by: Nathaniel <[email protected]>

* update plot sizes

Signed-off-by: Nathaniel <[email protected]>

* add pearl reference

Signed-off-by: Nathaniel <[email protected]>

* updating with Chris's comments and better parameterisation

Signed-off-by: Nathaniel <[email protected]>

---------

Signed-off-by: Nathaniel <[email protected]>