Re: Help on Project

*To*: mathgroup at smc.vnet.net*Subject*: [mg5069] Re: [mg5056] Help on Project*From*: stoev at plaza.snu.ac.kr*Date*: Fri, 25 Oct 1996 22:48:12 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Right now I do not have access to Mathematica, but as I remember InterpolatingFunction[] may help you. You have also Interpolate[]. Then you have two possibilities: First: Traditional solution. You interpolate acceleration and you Integrate[] twice with respect to your initial conditions (position and speed) and you get actual position and spped in every time moment. Second: Not so traditional solution. Interpolate[] uses some kind of spline interpolaton. That's why you can put your acceleration data in the interpolation of position as second derivatives of the position and also the moments in the time for which you have this accelerations. You must also put your initial conditions for some moment of time as initiol position and initial speed (let's say for t=0). Then spine interpolation does all the rest. You must be able to plot the result function. In both cases you must be prepared to have reletively big error in the result, because you integrate approximated data, but that's the data you have only. Maybe one of these algorithms is better for you, but this you must select by yourself. Intuitively I yould prefere the second solution, because the splines were invented (I think) for problems like this. In both cases you must see the syntaxis of functions you will use in the manual or in Mathematica. For ploting I can't help you in this moment. Julian Stoev On Wed, 23 Oct 1996, Keith Salmon wrote: > I am new to Mathematica and need help with a project. I have acceleration > data from the flight path of a missile that I would like to integrate to > get velocity and position relative to the launch point of the missile. The > acceleration information is referenced to a body axis which translates and > rotates with respect to the launch (inertial) axis. I want to be able to > plot in 2-D and 3-D the flight path to impact of the target and determine > impact angle and velocity. As I mentioned, I am not familiar with all the > inner workings of Mathematica and would appreciate any help building a > front end to the acceleration data that would allow future data to be > analyzed in the same fashion. Please email constructive suggestions to > salmonke at jupiter.hill.af.mil. Any and all help is appreciated. > Keith Salmon > > >