Re: How can I graph a characteristic equation dx/dt=v?????

*To*: mathgroup at smc.vnet.net*Subject*: [mg46560] Re: How can I graph a characteristic equation dx/dt=v?????*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Mon, 23 Feb 2004 22:33:42 -0500 (EST)*Organization*: Universitaet Leipzig*References*: <c1alsf$3o2$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de*Sender*: owner-wri-mathgroup at wolfram.com

Hi, may be http://support.wolfram.com/mathematica/graphics/2d/directionfield.html help you. Regards Jens HPerea at uswcl.ars.ag.gov wrote: > > I have a grid where I know the velocity v[x,t] in each node. What I want > to do is to graph the characteristic equation dx/dt=v using the velocity > values. I couldn't graph this equation correctly with Mathematica. In my > problem, if v->0 the characteristic curve has to be vertical and if > v->infinite the curve is horizontal. > o (x2,t2) > / | > / | > / | 1 This is a picture of my problem. > / | I know the velocity at the point (x1,t1) > / | but I don't know the point (x2,t2). > (x1,t1) o ---------o > 1 / v > > Do you think that I can graph the characteristic curves for this problem > using Mathematica?? > > I really appreciate your help.... > > Thanks > > Hugo Perea-Estrada > PhD. Student > The University of Arizona > Agricultural and Biosystems Engineering Department > Email: HPerea at uswcl.ars.ag.gov > hugop at ag.arizona.edu > hugo at email.arizona.edu