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?
>