求助 离散点生成的曲线加噪声

[nhmmiao]

已知x轴M=[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100];
y轴W=[25.9 26.4 25.6 26.1 25 27.0 25.2 25.8 26.1 23.8 23.9 23.0 23.6 23.6 23.3 23.5 23.7 23.8 23.9 23 23.9 23.2 23.0 23.1 23.9 23.7 23.9 23.5 23.9 23.6 23.9 23.6 23.1 23.4 23.5 23.1 23.2 23.7 23.6 23.6 23.6 23.9 23.0 23.1 23.2 23.7 23.1 23.2 23.9 23.1 23.2 23.5 23.7 23.0 23.0 23.1 23.4 23.0 23.7 23.5 23.8 23.9 23.7 23.9 23.0 23.9 23.0 23.1 23.9 23.3 23.3 23.1 23.5 23.6 23.1 23.2 23.8 23.9 23.0 23.9 23.1 23.3 23.8 23.6 23.8 23.1 23.2 22.0 22.9 22.9 22.8 22 22.7 22.1 22.9 22.0 22.1 22.8 22.7 22];
画出曲线用plot（M,W）；
可是我想在画出的曲线上加上随机噪声，请教如何加？谢谢

[slgu]

x=[1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100];
y=[25.9 26.4 25.6 26.1 25 27.0 25.2 25.8 26.1 23.8 23.9 23.0 23.6 23.6 23.3 23.5 23.7 23.8 23.9 23 23.9 23.2 23.0 23.1 23.9 23.7 23.9 23.5 23.9 23.6 23.9 23.6 23.1 23.4 23.5 23.1 23.2 23.7 23.6 23.6 23.6 23.9 23.0 23.1 23.2 23.7 23.1 23.2 23.9 23.1 23.2 23.5 23.7 23.0 23.0 23.1 23.4 23.0 23.7 23.5 23.8 23.9 23.7 23.9 23.0 23.9 23.0 23.1 23.9 23.3 23.3 23.1 23.5 23.6 23.1 23.2 23.8 23.9 23.0 23.9 23.1 23.3 23.8 23.6 23.8 23.1 23.2 22.0 22.9 22.9 22.8 22 22.7 22.1 22.9 22.0 22.1 22.8 22.7 22];
b=[26.92888, 0.022345144, -0.0000902372, 0.03600188];
fx=@(b,x)b(1)*exp(b(2)*x+b(3)*x.^2)./(1+b(4)*x);
y1=fx(b,x);
plot(x,y,'ko',x,y1,'markerfacecolor','k','linewidth',3)
legend('data','fit','location','north')