Hi erick in fact erick, there is an error!hehe. I did not realize before.
Em sexta-feira, 10 de junho de 2016 23:38:11 UTC-3, Erik Schnetter escreveu: > > When you write `(...)^1/8`, you probably mean `(...)^(1/8)` instead. > > -erik > > On Fri, Jun 10, 2016 at 10:29 PM, <[email protected] <javascript:>> > wrote: > >> this is the test for equation differential using runge-kutta45: f(x,y)= >> (-5*x - y/5)^1/8 + 10 >> >> >> <https://lh3.googleusercontent.com/-D6U4d5pN0pw/V1t3MaV3JpI/AAAAAAAAACU/-E_ceVhrTxkT3SAgmLUy5nHDhRJTIikSgCLcB/s1600/rk45.png> >> >> why the numerical result is different? I used : >> >> function Rk_JL() >> f(x,y)= (-5*x - y/5)^1/8 + 10 >> tspan = 0:0.001:n >> y0 = [0.0, 1.0] >> return ODE.ode45(f, y0,tspan);end >> >> >> and >> >> >> function [X1,Y1] = RK_M() >> f = @(x,y) (-5*x - y/5)^1/8 + 10; >> tspan = 0:0.001:n; >> y0 = 1 >> [X1,Y1]= ode45(f,tspan,1);end >> >> > > > -- > Erik Schnetter <[email protected] <javascript:>> > http://www.perimeterinstitute.ca/personal/eschnetter/ >
