I want to create a 'if' for a probability

How would I write that the prbability that I eat carrots this year knowing that I ate carrots last year is of 80%. And that the probabilities that I eat carrots this year knowing I didnt eat carrots last year is of 40%. Could you please help me out with this?

Answer 1

[Voss]

ate_carrots_last_year = false;

if ate_carrots_last_year
    P_eat_carrots_this_year = 0.8;
else
    P_eat_carrots_this_year = 0.4;
end