帮帮忙,看下哪里错了..


%xw 给定常量
K=1.38e-19;
T=300;
Q=1.6e-19;
Is=10e-12;
%绘制电压电流图
KT=K*T/Q;
Ud=0:0.01:3.5;
Id=Is*(exp(Ud/KT)-1);
plot(Ud,Id),grid on
axis([0,max(Ud),0,100]),hold on
%线路图的绘制
line([1.5,1.8],[76,76])
fill([1.8,2,2,1.8],[76,72,80,76],'K')
line([1.8,1.8],[72,80],'linewidth',2)
line([2,2.5],[76,76])
line([2.5,2.8,2.8,2.5,2.5],[74,74,78,74],...'linewidth',2)
line([2.8,3.1],[76,76])
plot([1.5,2.2,3.1],[76,76,76],'o')
text(1.4,70,'0'),text(2.1,70,'Ud'),
txet(2.6,68,'Rf'),text(3,70,'Ud'),
%
UO=input('UO=[伏]'),
Rf=imput('Rf=[欧姆]')
Id1=1000*(UO-Ud)./Rf;
plot(Ud,[Id;Id1])
grid on
%
[di,nI]=min(abs(Id-Id1));
Udx=Ud(nI);
Idx=Id1(nI);
text(Udx,Idx,['Udx,Idx=(',num2str(Udx),'V,',num2tr(Idx),'mA)'])
hold off
legend('二极管特性及工作点的确定)
xlabel('Ud(V)'),ylabel(Id(mA)')