matlab有关画图题，请尽快求解！

Question

Answer 1

你好，代码供参考：

% 1(1)
figure(1);clf
x = linspace(0,2*pi,100);
y1 = x.^2;
y2 = cos(2*x);
y3 = y1.*y2;
plot(x,y1,'k',x,y2,'b',x,y3,'r')
legend('y1=x^2','y2=cos(2*x)','y3=y1*y2')

% 2
figure(2);clf
data = [3000, 2334, 3444,6663; ...
    2342,3422,2111,4453; 3232, 2334,5433,3500];
bar(data)
set(gca,'xticklabel',{'海尔','联想','方正'})
legend('2006','2007','2008','2009')

% 3
figure(3);clf
y1 = wgn(1000,1,4);
subplot(2,2,1:2)
plot(y1,'k.'); title('高斯噪声散点图')
x = linspace(0,2*pi,101);
y2 = 2*exp(-0.5*x);
y3 = 2*exp(-0.5*x).*sin(2*pi*x);
x4 = 0:0.5:2*pi; y4 = zeros(size(x4));
y5 = 2*exp(-0.5*x4);
subplot(2,2,3)
plot(x,y2,'k-.',x,-y2,'k-.'); hold on;
plot(x,y3,'b--')
plot(x4,y4,'rp'); axis([0,6,-2,2])
subplot(2,2,4);
bar(x4,y5,'g');axis([-0.3,7,-0,2])

题量太大了，给你做三道吧，呜呜