Question

用四阶龙格-库塔求微分方程在matlab中,四阶龙格-库塔公式怎么用在微分方程f(s)=10/(s4+8s3+36s2+

Answer 1

fun=@(s,f)10./(s.^4+8*s.^3+36*s.^2+40*s+10);

s0=0;

send=1;

ds=0.001;

s=s0:ds:send;

f=0; %初值

i=1;

for ss=s(1:end-1)

k1=fun(ss,f(i));

k2=fun(ss+ds/2,f(i)+ds/2*k1);

k3=fun(ss+ds/2,f(i)+ds/2*k2);

k4=fun(ss+ds ,f(i)+ds*k3);

f(i+1)=f(i)+ds/6*(k1+2*k2+2*k3+k4);

i=i+1;

end

plot(s,f);