RE: Perform an assigment
- To: mathgroup at smc.vnet.net
- Subject: [mg43893] RE: [mg43865] Perform an assigment
- From: "David Park" <djmp at earthlink.net>
- Date: Fri, 10 Oct 2003 03:06:03 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Paulo, Generally, I would recommend against assigning values to your variables. Using the Rules that the Solve routine returns is often more convenient. If you assign values you can no longer use the variables as symbols until you Clear them. Nevertheless, the following is how you can do it. eqns = {2x + 3y == 5, x - y == 2}; sols = Solve[eqns, {x, y}][[1]] x = x /. sols y = y /. sols {x -> 11/5, y -> 1/5} 11/5 1/5 But now see what happens is you try to evaluate the statements again. (Say you decided you wanted 3 x + 3 y in the first equation.) Instead, you can use the rules to substitute into expressions on a controlled basis and continue to use x and y as symbolic variables. Clear[x, y] sols = Solve[eqns, {x, y}][[1]] x^2 + 3x y /. sols 154/25 David Park djmp at earthlink.net http://home.earthlink.net/~djmp/ From: paulocct at uniquindio.edu.co [mailto:paulocct at uniquindio.edu.co] To: mathgroup at smc.vnet.net Hi all, I want to solve a system of equations and to assign the values calculated to the variables of the system automatically, What should I do?. What command should I use? Thanks a lot, Paulo Carmona University of Quindio Colombia