Let $\Omega$ be a convex, closed, compact set in $\mathbb{R}^d$ with a smooth boundary.
Given a data $(x_i,d_i)$, $x_i \in \Omega$,$d_i \in \mathbb{R}$, $i = 1,2,3...N$, and $\sum\limits_{i=1}^N d_i = 0$
I want to find a function $f:\Omega \to \mathbb{R}$, such that,
$\int_{\Omega}f(x)dx = ...
In number theory, Euler's totient function counts the positive integers up to a given integer n that are relatively prime to n. It is written using the Greek letter phi as φ(n) or ϕ(n), and may also be called Euler's phi function. It can be defined more formally as the number of integers k in the range 1 ≤ k ≤ n for which the greatest common divisor gcd(n, k) is equal to 1. The integers k of this form are sometimes referred to as totatives of n.
For example, the totatives of n = 9 are the six numbers 1, 2, 4, 5, 7 and 8. They are all relatively prime to 9, but the other three numbers in this range...
