Different "kind" of variable

Hi, I would like to ask you how could I create different "kinds" of variable. I am going to create school project about food-macros tracking in Matlab. I need to create three "kinds" of variable - carbohydrates, fats and proteins and I need them to sum by their "kind". How can I do this ?

Thanks, all answers are welcomed !

[Rik]

If you come up with a specific example of how your data should look and what output you expect it will be easier to give you advice.

[Jan Horacek]

In that program there will be list of food with their macros per 100g/100ml, for example oats (66g carbs, 10g proteins, 7g fats) and milk (12g carbs, 8g proteins, 8g fats) and I need to sum all these macros separately. For example: 50g of oats and 200g of milk means 66/2 + 2*12 CARBS, 10/2 + 2*8 PROTEINS and 7/2 + 2*8 FATS. I hope you understand.

Answer 1

[Stephen23]

typ = ["oats","milk","water"]

typ = 1×3 string array
    "oats"    "milk"    "water"

mat = [66,12,0;10,8,0;7,8,0]

mat = 3×3

66 12 0 10 8 0 7 8 0

 inp = ["milk","oats"];
 qty = [2,0.5];
 [~,idx] = ismember(inp,typ);
 out = qty*mat(idx,:)

out = 1×3

53 22 0

[Jan Horacek]

Thanks !!!