fi=0:0.2:pi;
ys=sin(fi);
yc=cos(fi);
h=figure;
set(h,'color','w');
set(gca,'xcolor','w');
set(gca,'ycolor','w');
hold all
plot(fi,ys,'-g','LineWidth',2)
plot(fi,yc,'-r','LineWidth',2)
plot([fi(1) fi(end)],[0 0],'-k')
%text(fi(end)-0.3,0.05,'\rightarrow')
plot([fi(end) fi(end)-0.1],[0 0.02])
plot([fi(end) fi(end)-0.1],[0 -0.02])
plot([0 0],[min(min(ys),min(yc))  max(max(ys),max(yc))*1.1],'-k')
xlabel('fi','Color','k')
ylabel('y','Color','k','Rotation',0)
legend('sin(fi)', 'cos(fi)')
axis([-0.2 3.5 -1.1 1.1])
%% 3D
x=1:0.5:40;
y=2:2:50;
xm=zeros(size(x,2),size(y,2));
ym=zeros(size(xm));
for i=1:size(x,2)
    for j=1:size(y,2)
        xm(i,j)=x(i);
        ym(i,j)=y(j);
    end
end
zm=sin(xm).*ym;
h=figure;
mesh(xm,ym,zm)
figure
surf(xm,ym,zm)
figure
meshc(xm,ym,zm)
figure
contour(xm,ym,zm)