各位好心的大侠帮忙看下这个warning是什么意思！！谢谢啦！！
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Warning: Failure at t=1.547794e+000.Unable to meet integration tolerances without reducing the step size below the
smallest value allowed (3.552714e-015) at time t.
> In ode15s at 753
In modfun1 at 6
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
是什么意思？是我的方程有问题还是程序有问题？各位帮帮忙吧！！
积分的步长强制变小了. 应该结果可信,自己再确认一下. 可是为什么不是我想要的结果！！而且根本不对啊！！下面是我的程序！！帮忙看下哪里有错误！！谢谢了@！
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
clear all
clc
tspan=;
x0=;
options=odeset('RelTol',1e-6);
=ode15s(@modfun,tspan,x0,options);
figure;
plot(t,x(:,1),'r-');
hold on;
plot(t,x(:,2),'k:');
hold on;
plot(t,x(:,3),'b:');
hold on;
plot(t,x(:,4),'k-');
hold on;
plot(t,x(:,5),'r:');
set(gca,'Fontsize',12);
xlabel('\itt','Fontsize',16);
legend('x1','x2','x3','x4','x5')
function dx=modfun(t,x)
rc=(0.125-3.78*x(3))^1/3;
d1=1.467*10^-6*x(4)^1.75;
d2=3.828*10^-7*x(4)^1.75;
k1=0.225*exp(-179.14/x(4));
k2=0.650*exp(-342.4324/x(4));
r1=-(4*pi*rc^2*(2.3616*10^-5-x(1)))/(1/k1+rc/d1-4*rc^2/d1);
r2=-(4*pi*rc^2*(1.549*10^-5-x(2)))/(1/k2+rc/d2-4*rc^2/d2);
cpg=(2*(2.3616*10^-5-x(1))*(6.52+7.8*10^-2*x(4)+0.12*10^5*x(4)^-2)+28*(1.549*10^-5-x(2))*(6.79+9.8*10^-2*x(4)-0.12*10^5*x(4)^-2)+18*(2.308*10^+6-x(1))*(7.3+2.46*10^-3*x(4))+44*(1.1027*10^-6+x(2))*(10.57+2.1*10^-3*x(4)-2.06*10^5*x(4)^-2)+16*2.0759*10^-6*(5.65+11.44*10^-3*x(4)-0.46*10^5*x(4)^-2))/(60.4229+16*x(1)+16*x(2));
gms=2533.3*(-4.4864*rc^3+0.0069)/(-0.0342*rc^3+0.0069);
cps=(3.4+0.006*x(5)*rc^3+79.9140*rc^3)/(0.3875-0.3*rc^3);
h1=8921.1-3.79*x(5)+5.466*10^-4*x(5)^2-1.2*10^4*x(5)^-1;
h2=-2472.6-0.79*x(5)+0.266*10^-3*x(5)^2+1.95*10^5*x(5)^-1;
dx=[-0.99/1.98*10^8*r1;...
-0.99/1.98*10^8*r2;...
-0.99/4.56*10^4*(r1+r2);...
0.99*pi*4*10^4*(x(5)-x(4))/(cpg*8.8419*10^3);...
0.99*(pi*4*10^4*(x(5)-x(4))-h1*r1-h2*r2)/gms/cps];
dx=dx(:);
return
问题出在哪里！！帮忙看下是不是程序错了！！十分感谢！！
页:
[1]