#MATHSTODON
can anyone help me with this?
let's say you have a rational number n
what's the best way of computing the shortest list of integers whose mean average is n?
the result could be represented as a list (where some numbers are stated multiple times) e.g:
n = 4.75
avg([7, 7, 4, 1]) = 4.75
or as a set of tuples where the second value is the number of times that number occurs, e.g:
n = 4.75
[ {7, 2}, {4, 1}, {1, 1} ]
@jk do you have a rational representation of the number? a/b?
@yatchi turns out not always :/ so it has to work for all real numbers
@ninjawedding @jk yeah the average must be a rational number, you can't do this with an irrational number
@yatchi @ninjawedding accuracy isn't paramount so I can just truncate to a rational approximation anyway; it seems fairly workable
@jk @ninjawedding the shortest possible list will be produced by the best rational approximation which you can calculate with continued fractions
@jk in any case, i think you get there by finding the sum and the number of integers that are in the list (and for any given sum you can trivially get a list by adding the right number of zeros. and work from there if you want one of the infinite other possibilities). if a/b is in simplest form then ab is the sum and b is the number of numbers required, because there is no smaller integer a/b can be multiplied by to produce an integer
@yatchi thanks this is helpful!
@jk oops i mean a is the sum
@jk so for 4.75 = 19/4 you need four numbers that sum to 19, and there is no way to do it with fewer than four
and then if you want to do it for a real number the problem is then finding a rational representation of it
@jk I love this because I understand it to exist in the world that I exist in and I have absolutely no idea what even a rational number n might be.
The diversity of experience.
or real number n, i guess,