texte1 = text("moteur", (3.5,-0.7),rotation=40,color="black",background_color="white")
texte2 = text("résistant", (0.5,2.7),rotation=220,color="black",background_color="white")
chemin = circle ((2, 1), 2, color = "plum") 
E(x,y)=(x^2,y^2)
(xminn,xmaxx,yminn,ymaxx)=(-0.5,4.5,-1.5,3.5)



# -------
champ = plot_vector_field(E,(x,xminn,xmaxx),(y,yminn,ymaxx))
tout=champ+chemin+texte1+texte2
show(tout)
tout.save('circulation_1.png', xmin=xminn, xmax=xmaxx, ymin=yminn, ymax=ymaxx)

texte1 = text("moteur", (3.5,-0.7),rotation=40,color="black",background_color="white")
texte2 = text("résistant", (0.5,2.7),rotation=220,color="black",background_color="white")
demicercle(x)=sqrt(4-(x-2)^2)+1
chemin = plot(demicercle,(0,4))

E(x,y)=(x^2,y^2)
(xminn,xmaxx,yminn,ymaxx)=(-0.5,4.5,-1.5,3.5)



# -------
champ = plot_vector_field(E,(x,xminn,xmaxx),(y,yminn,ymaxx))
tout=champ+chemin+texte1+texte2
show(tout)
tout.save('circulation_2.png', xmin=xminn, xmax=xmaxx, ymin=yminn, ymax=ymaxx)