Hi, I have the following equation: x1 + x2 + x3 - 2(x4 + x5 + x6) + 3(x7) = N each x_i can take any value: 1, 2, 3, 5, 6, 10, 15 or 30 and each one is different from each other. Which combination of values ??in the formula which leads to the smallest value of N? How can I program this situation? -------------------------------------- Silvano Cesar da Costa Departamento de Estat?stica Universidade Estadual de Londrina Fone: 3371-4346
Challenge
2 messages · Silvano, Berend Hasselman
On 22-02-2012, at 13:49, Silvano wrote:
Hi, I have the following equation: x1 + x2 + x3 - 2(x4 + x5 + x6) + 3(x7) = N each x_i can take any value: 1, 2, 3, 5, 6, 10, 15 or 30 and each one is different from each other. Which combination of values ??in the formula which leads to the smallest value of N? How can I program this situation?
I hope this isn't homework. library(gtools) val <- c(1,2,3,5,6,10,15,30) x.vals <- permutations(n=length(val),r=7,v=val) f <- function(x) x[1]+x[2]+x[3]-2*(x[4]+x[5]+x[6])+3*x[7] fun.vals <- apply(x.vals,1, function(z) f(z)) minidx <- which.min(fun.vals) fun.vals[minidx] x.vals[minidx,] f(x.vals[minidx,]) Berend Hasselman