《正向边界曲线》PPT课件.ppt

正向边界曲线,April 24,2012,一个平面区域的边界曲线的正向是这样规定的：当你沿着边界的正向行走时，你附近的区域总是在你的左边。以下动画显示了正向边界曲线的方向。,动画的Maple程序with(plots):x:=t-2*cos(t):y:=t-sin(t):Quxian:=plot(x(t),y(t),t=0.2*Pi,thickness=5,color=gray,filled=true):K:=40:for i from 1 to K doti:=i*2*Pi/K:quxiani:=plot(x(t),y(t),t=0.ti,thickness=3):od:quxian:=display(seq(quxiani,i=1.K),insequence=true):display(quxian,Quxian,scaling=constrained);,动画的Maple程序with(plots):x1:=t-4*cos(t):y1:=t-2*sin(t):x2:=t-cos(t):y2:=t-sin(t):Quxian1:=plot(x1(t),y1(t),t=0.2*Pi,color=green,filled=true):Quxian2:=plot(x2(t),y2(t),t=0.2*Pi,color=white,filled=true):K:=50:for i from 1 to K doti:=i*2*Pi/K:quxian1i:=plot(x1(t),y1(t),t=0.ti,thickness=4):quxian2i:=plot(x2(-t),y2(-t),t=0.ti,thickness=4):od:quxian1:=display(seq(quxian1i,i=1.K),insequence=true):quxian2:=display(seq(quxian2i,i=1.K),insequence=true):display(quxian2,quxian1,Quxian2,Quxian1,scaling=constrained);,动画的Maple程序with(plots):x1:=t-4*cos(t):y1:=t-2*sin(t):x2:=t-1.4*cos(t)-1:y2:=t-1.2*sin(t):x3:=t-cos(t)+2:y3:=t-sin(t)/2:Quxian1:=plot(x1(t),y1(t),t=0.2*Pi,color=gray,filled=true):Quxian2:=plot(x2(t),y2(t),t=0.2*Pi,color=white,filled=true):Quxian3:=plot(x3(t),y3(t),t=0.2*Pi,color=white,filled=true):K:=50:for i from 1 to K doti:=i*2.5*Pi/K:quxian1i:=plot(x1(t),y1(t),t=0.ti,thickness=4):quxian2i:=plot(x2(-t),y2(-t),t=0.ti,thickness=4):quxian3i:=plot(x3(-t),y3(-t),t=0.ti,thickness=4):od:quxian1:=display(seq(quxian1i,i=1.K),insequence=true):quxian2:=display(seq(quxian2i,i=1.K),insequence=true):quxian3:=display(seq(quxian3i,i=1.K),insequence=true):display(quxian3,quxian2,quxian1,Quxian3,Quxian2,Quxian1,scaling=constrained);,