rou=0.45869;
V=210;
W=100000;
S=pi/4;
B=38.05;
n=1;
To=n*W/(rou*V*S*B);
Vo=To/(2*pi*pi*B/4);
t0=S*B/Vo;
epsilu=0.452;
epsiluxin=(epsilu*pi*B/4).^(1/3)/Vo;
if epsiluxin>0.2535
   Tcxin=t0*(0.7475/epsiluxin).^(3/4);
else if epsiluxin>0.0121&&epsiluxin<0.2535
     epsiluxin=(Tcxin/t0)^0.25*exp(-0.7*Tcxin/t0);
else if epsiluxin<0.0121&&epsiluxin>0.001
     Tcxin=t0*(-180*epsiluxin+9.18);
else if epsiluxin<0.001
     Tcxin=9*t0;
t=500;
N=0.01;
TaoT=To*(1.1-10.0.^[-5t0/(Tcxin+5t0)])*exp((-0.452+0.25(N*t0).^2.)*(t-Tcxin)/Tcxin);
plot(t,TaoT);
Vwx=0;
Vwy=0;
X1=X2=(V+Vwx)*t;
Y1=-B+Vwy*t;
Y2=B+Vwy*t;
Z1=Z2=-2*TaoT/(pi*pi*B);
Y=10;
Z=20;
Rc=0.04*B;
Uy=TaoT*(Z-Z1)/(2*pi*((Y-Y1).^2+(Z-Z1).^2+Rc.^2))+TaoT*(Z-Z2)/(2*pi*((Y-Y2).^2+(Z-Z2).^2+Rc.^2));
Uz=TaoT*(Y-Y1)/(2*pi*((Y-Y1).^2+(Z-Z1).^2+Rc.^2))+TaoT*(Y-Y2)/(2*pi*((Y-Y2).^2+(Z-Z2).^2+Rc.^2));
U=sqrt(Uy.^2+Uz.^2);
Plot3(Y,Z,U);

请高手多多帮助  谢谢

if epsiluxin>0.2535
   Tcxin=t0*(0.7475/epsiluxin).^(3/4);
else if epsiluxin>0.0121&&epsiluxin<0.2535
     epsiluxin=(Tcxin/t0)^0.25*exp(-0.7*Tcxin/t0);
else if epsiluxin<0.0121&&epsiluxin>0.001
     Tcxin=t0*(-180*epsiluxin+9.18);
else if epsiluxin<0.001
     Tcxin=9*t0;
你上面的这段代码没有end

end  加了 也还是有问题，那 个t 应该是个 自变量而不是定值，请帮忙改正

把你的错误信息发上来吧