x=0:0.1:15;
y=cos(x);
colormap(copper); %通过修改颜色map来修改填充的颜色。
area(x,y);
https://jingyan.baidu.com/article/d71306353c754813fcf4756d.html
https://blog.csdn.net/fresh_hit_man/article/details/79670678
https://blog.csdn.net/qq_45721778/article/details/107496928
https://blog.csdn.net/weixin_45592298/article/details/106001523
https://blog.csdn.net/MATLAB_matlab/article/details/53868335
