Thread: a nonlinear problem

I am not sure that I post at the right palce, because I don't know which topic my problem should belong to. So sorry for that.

Given some variables a1, a2, a3... an, and some constraints based on these variables, like:
a1 + a2 >0,
a3 - a5 >0,
a4 - a3 + a2 <0,
....
How to get a solution for variables, that maximun the positive number of variables. That means, make as much of
the variables positive. I even don't know which area this topic should belong to. Please help. Thanks in advance!
steve

In general, if you have a non-linear problem in which you have to maximise or minimise something whilst paying due consideration to constrain equations, it's a problem of non-linear programming.

where represents your constraint equations.

But is there any practical way to solve it?

Try gnumeric.

Originally Posted by zhu1984

I am not sure that I post at the right palce, because I don't know which topic my problem should belong to. So sorry for that.

Given some variables a1, a2, a3... an, and some constraints based on these variables, like:
a1 + a2 >0,
a3 - a5 >0,
a4 - a3 + a2 <0,
....
How to get a solution for variables, that maximun the positive number of variables. That means, make as much of
the variables positive. I even don't know which area this topic should belong to. Please help. Thanks in advance!
steve

I'd like to guide you to a practical solution to this problem, but I'm not sure if you've given us the full problem, have you?

In your question, you said you had n variables, and gave us three constraint equation which involved only 5 of those n variables. How many variables are there, and are there any more constraint equations?

The number of variables can be 200 or more. And all of the variables are involved in constraints. The example I gave may not clear enough.