我想对函数进行积分，可总出不来结果，为什么啊？
L=0.000771,R=3.54,C=0.0000022,uc0=200;<BR>alpha=R/2/L,wn=sqrt(1/L/C),beta=sqrt(wn^2-alpha^2);<BR>A=sqrt((beta*uc0)^2+alpha*uc0^2)/beta,fy=atan(beta/alpha);<BR>f=t*exp(-2*alpha*t).*sin(beta*t+fy).*cos(beta*t);<BR>e=wn.*C.*(A^2).*int(f,t,0,0.002);<BR>plot(e)<BR>L =<BR>7.7100e-004<BR>R =<BR> 3.5400<BR>C =<BR>2.2000e-006<BR>alpha =<BR>2.2957e+003<BR>wn =<BR>2.4281e+004<BR>A =<BR>200.0004<BR><FONT color=#ff3300>??? Error using ==> plot<BR>Conversion to double from sym is not possible.<BR><BR></FONT><FONT color=#000000>请高手予以指正，谢谢了！</FONT> 不是没积出来，是没画出来<BR>提示的错误是plot命令误用<BR>PLOT(X,Y) ，x为横坐标，y为纵坐标<BR>你只给了y，给2个坐标试试 <P>谢谢xueyi<BR>我将其改为如下，可依然出不来运行结果阿,为什么运行出不来beta的值？最后结果也不能出来？<BR>L=0.000771,R=3.54,C=0.0000022,uc0=200;<BR>alpha=R/2/L,wn=sqrt(1/L/C),beta=sqrt(wn^2-alpha^2);<BR>A=sqrt((beta*uc0)^2+alpha*uc0^2)/beta,fy=atan(beta/alpha);<BR>e=wn*C*(A^2)*int(t*exp(-2*alpha*t).*sin(beta*t+fy).*cos(beta*t),t,0,0.002);<BR>plot(t,e)<BR><BR>运行结果如下：<BR>L = 7.7100e-004<BR>R =3.5400<BR>C =2.2000e-006<BR>alpha =2.2957e+003<BR>wn =2.4281e+004<BR>A =200.0004</P><P><FONT color=#ff3300>??? Error using ==> mtimes<BR>Inner matrix dimensions must agree.<BR></FONT></P>
回复：（风中的使者）我想对函数进行积分，可总出不来...
t未定义[此贴子已经被作者于2005-12-23 9:05:07编辑过]
多谢！
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