Re: How to easily set up all coefficients to be positive in Solving an integer equation?

*To*: mathgroup at smc.vnet.net*Subject*: [mg124358] Re: How to easily set up all coefficients to be positive in Solving an integer equation?*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Tue, 17 Jan 2012 03:33:12 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

n = 5; var = Array[x, n]; coef = RandomInteger[{-10, 10}, n]; Solve[Flatten[{coef.var == 0, Thread[var > 0]}], var, Integers] Bob Hanlon On Mon, Jan 16, 2012 at 5:11 PM, Rex <aoirex at gmail.com> wrote: > Given a vector `A==[a_1, a_2, a_3,...,a_n]`, where a_i are integers, > now > solving an equation > `=E2=88=91a_i * x_i==0` with all x_i>==0, and x_i to be integers. > > We can write some code like this > `Solve[A . Table[x[i], {i, n}] == 0 && Table[x[i] > 0, {i, n}], > Integers]` > > But the conditions above `Table[x[i] > 0` is not rightly coded. That > should be > `x[1]>0 && x[2]>0 && x[3]>0 &&...x[n]>0` > Is there any easy way to write such code? >