1. The problem statement, all variables and given/known data I need to get a general function in 2 variables f(m,n). The task is to find a general function f(m,n) with these terms: The function has to be periodic. The function has to include those blue and red points in each example. The value of the function has to be f(m,n) =1 ONLY in blue points, and the value of the function has to be f(m,n)=0 ONLY in red points. The look of the function isn't important as long as it complies with previous terms. 2. Relevant equations You can see a graphicon with charasteristic points: In the first example m=2 (m is period). In the next example m=3: For m=4: and so on. 3. The attempt at a solution In first example (for m=2) I used functions: sin and absolute, but for all other m, it is not possible with only those functions, I also tried use the Fourier series but I dont have so much knowledge in mathematics to built a such function. Does somebody know how to do it?