fix: some fixes and experiments

[stephanegigandet]

Main changes:

• compute percent_estimate for parent ingredients (by summing the quantities of child ingredients), as the metrics will be computed on them if they have specified percent on the products
• use [nutrient]_100g fields, as [nutrient] can be per serving or per 100g
• refactored the relative constraints on ingredients, as they were not applied to children of the last ingredient
• added a constraint that the sum of children is equal to the parent
• added the minimization of the maximum distance between subsequent ingredients
• experimenting with weights of nutrients
• completely remove the nutrient contribution of ingredients without ciqual codes, as having min = 0 and max = 100 for them seems to make the whole nutrient distance not used: the percent of ingredients seeem to be distributed in an equitable way...
  e.g. for Nutella:

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ingredient	ciqual_food_code	ciqual_proxy_food_code	total_percent_estimate	total_difference	number_of_products	number_of_products_where_specified
en:fat-reduced-cocoa			3,52	3,88	1	1
en:hazelnut-oil	17210		14	0,977	1	1
en:palm-oil	16129		14	0	1	0
en:skimmed-milk-powder	19054		3,52	3,08	1	1
en:soya-lecithin	42200		3,52	0	1	0
en:sugar		31016	54,4	0	1	0
en:vanillin			3,52	0	1	0
en:whey-powder			3,52	0	1	0

[john-gom]

I'm not sure that this is a good way to do it. It might be better just to keep ingredients without a CIQAL code completely out of the optimisation and then just add them back in at the end, half way between their greater and lesser ingredient

[stephanegigandet]

Well we do need the solver to know about ingredients without CIQUAL code even if we consider that they don't have any nutrient contribution, as they add constraints on the other ingredients.
e.g. if we have "unknown, sugar, oil", then sugar must be 50% or less.

[john-gom]

I'm not sure what these changes are trying to do but they have broken the unit tests around quantity_estimates and evaporation. The idea of the quantity_estimate is that it is the amount of original ingredient that is needed to make 100g of the product, i.e. the quantity before evaporation

[stephanegigandet]

It's still the same definition of quantity_estimate, except that it adds quantity estimates for parent ingredients as well.

[john-gom]

Is this a permanent change or just an experiment? Breaks a unit test (I have commented the test for now).

[stephanegigandet]

I tried many values and looked at the resulting accuracy: https://docs.google.com/document/d/1NFg2lAaDzSkRldKU6uDGcjPVxbfTsc9p59r7L6OEqiQ/edit#heading=h.fl6o8g6m5uv5

So far it's the best I found.