是否可以 plot 一个带有箭头的图形，如 MATLAB 中所附的图像所示？

Question

Can I draw such a plot in Matlab? If not what would be the right software to draw it? Later, I need to paste figure in MS word file.

Answer 1

Sure, you need the annotation function, eg

figure('Color','w');
plot(-pi:0.01:pi,sin(-pi:0.01:pi));
ax=gca();
set(ax,'YAxisLocation','left','XAxisLocation','bottom','Box','off','XTick',[],'YTick',[])
annotation('textarrow',[0.4,0.5],[0.4,0.5],'String','P')
annotation('arrow',[ax.Position(1),sum(ax.Position([1,3]))],ax.Position([2,2]),'LineWidth',0.5);
annotation('arrow',ax.Position([1,1]),[ax.Position(2),sum(ax.Position([2,4]))],'LineWidth',0.5);
annotation('textbox',[ax.Position(1)-0.05,sum(ax.Position([2,4]))-0.05,0.05,0.05],'String','Q','EdgeColor','none')
annotation('textbox',[sum(ax.Position([1,3]))-0.05,ax.Position(2)-0.05,0.05,0.05],'String','R','EdgeColor','none')