matlab指数增长和阻滞增长拟合代码(4页).doc

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1、-matlab指数增长和阻滞增长拟合代码-第 4 页代码：t=1:13;x=3.04,6.63,11.13,28.43,49.22,87.85,134.11,200.00,208.69,303.03,410.73,580.00,728.57;c=0.40,0.97,2.31,4.45,7.63,10.11,19.86,33.44,38.03,75.07,112.08,152.39,226.55;d=2.06,2.35,3.17,8.06,15.22,28.82,43.31,54.67,55.83,75.26,102.01,174.05,200.95;e=0.54,1.18,1.98,5.06,

2、8.77,15.65,23.89,36.63,37.17,53.98,73.16,123.31,159.78;%指数增长模型y=log(x);cc=log(c);dd=log(d);ee=log(e);a=polyfit(t,y,1);h= polyfit(t,cc,1);i= polyfit(t,dd,1);k= polyfit(t,ee,1);r=a(1);r2=h(1);r3=i(1);r4=k(1);x0=exp(a(2);x1=x0*exp(r*t);c0=exp(h(2);c1=c0*exp(r2*t);d0=exp(i(2);d1=d0*exp(r3*t);e0=exp(k(2)

3、;e1=e0*exp(r4*t);%阻滞增长模型f=(a,t) a(1)./(1+(a(1)/x(1)-1)*exp(-a(2)*(t-t(1);f=(h,t) h(1)./(1+(h(1)/c(1)-1)*exp(-h(2)*(t-t(1);f=(i,t) i(1)./(1+(i(1)/d(1)-1)*exp(-i(2)*(t-t(1);f=(k,t) k(1)./(1+(k(1)/e(1)-1)*exp(-k(2)*(t-t(1);a=lsqcurvefit(f,800 1,t,x);h=lsqcurvefit(f,800 1,t,c);i=lsqcurvefit(f,800 1,t,d)

4、;k=lsqcurvefit(f,800 1,t,e);figure(1);subplot(2,1,1);plot(t,x,o,t,x1,r:.);x2=f(a,t);plot(t,x,o,t,x1,r:.,t,x2,g*-)legend(原始数据,指数增长模型,阻滞增长模型,2)xlabel 时间段ylabel 公众号总量（万）title(资讯类);figure(1)subplot(2,1,2);plot(t,c,o,t,c1,r:.);c2=f(h,t);plot(t,c,o,t,c1,r:.,t,c2,g*-)legend(原始数据,指数增长模型,阻滞增长模型,2)xlabel 时间段y

5、label 公众号总量（万）title(生活类);figure(2)subplot(2,1,1);plot(t,d,o,t,d1,r:.);d2=f(i,t);plot(t,d,o,t,d1,r:.,t,d2,g*-)legend(原始数据,指数增长模型,阻滞增长模型,2)xlabel 时间段ylabel 公众号总量（万）title(娱乐类);figure(2)subplot(2,1,2);plot(t,e,o,t,e1,r:.);e2=f(k,t);plot(t,e,o,t,e1,r:.,t,e2,g*-)legend(原始数据,指数增长模型,阻滞增长模型,2)xlabel 时间段ylabe

6、l 公众号总量（万）title(其他);参数资讯类生活类娱乐类其他类公众号总量程序代码：x=1:2:26; y=3.04,6.63,11.13,28.43,49.22,87.85,134.11,200.00,208.69,303.03,410.73,580.00,728.57;b=2.04,2.14,3.68,10.86,17.60,33.27,47.05,75.26,77.66,88.72,123.48,130.25,141.29;c=0.40,0.97,2.31,4.45,7.63,10.11,19.86,33.44,38.03,75.07,112.08,152.39,226.55;d=2

7、.06,2.35,3.17,8.06,15.22,28.82,43.31,54.67,55.83,75.26,102.01,174.05,200.95;e=0.54,1.18,1.98,5.06,8.77,15.65,23.89,36.63,37.17,53.98,73.16,123.31,159.78;st_ = 500 30 0.2 ;ft_ = fittype(a0/(1+b0*exp(-k0*(x-1),. dependent,y,independent,x,. coefficients,a0, b0,k0);cf_ = fit(x,y,ft_,Startpoint,st_)plot(

8、cf_,fit,0.95);hold on,plot(x,y,ro)f1t_ = fittype(a1/(1+b1*exp(-k1*(x-1),. dependent,b,independent,x,. coefficients,a1, b1,k1);c1f_ = fit(x,b,f1t_,Startpoint,st_)plot(c1f_,fit,0.95);hold on,plot(x,b,g*)f2t_ = fittype(a2/(1+b2*exp(-k2*(x-1),. dependent,c,independent,x,. coefficients,a2, b2,k2);c2f_ =

9、fit(x,c,f2t_,Startpoint,st_)plot(c2f_,fit,0.95);hold on,plot(x,c,b+)f3t_ = fittype(a3/(1+b3*exp(-k3*(x-1),. dependent,d,independent,x,. coefficients,a3, b3,k3);c3f_ = fit(x,d,f3t_,Startpoint,st_)plot(c3f_,fit,0.95);hold on,plot(x,d,*)f4t_ = fittype(a4/(1+b4*exp(-k4*(x-1),. dependent,e,independent,x,. coefficients,a4, b4,k4);c4f_ = fit(x,e,f4t_,Startpoint,st_)plot(c4f_,fit,0.95);hold on,plot(x,e,yo)