matlab指數(shù)增長(zhǎng)和阻滯增長(zhǎng)擬合代碼

1、精選文檔代碼：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=0.54,1.18,1.98,5.06,8.77,15.65,23.89,36.63

2、,37.17,53.98,73.16,123.31,159.78;%指數(shù)增長(zhǎng)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);e1=e0*exp(r4*t);%阻滯增長(zhǎng)

3、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);k=lsqcurvefit(f,800 1

4、,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('原始數(shù)據(jù)','指數(shù)增長(zhǎng)模型','阻滯增長(zhǎng)模型',2)xlabel 時(shí)間段ylabel 公眾號(hào)總量（萬(wàn)）title('資訊類(lèi)');figure(1)subplot(2,1,2);plot(t,c,'o',t,c1,'

5、r:.');c2=f(h,t);plot(t,c,'o',t,c1,'r:.',t,c2,'g*-')legend('原始數(shù)據(jù)','指數(shù)增長(zhǎng)模型','阻滯增長(zhǎng)模型',2)xlabel 時(shí)間段ylabel 公眾號(hào)總量（萬(wàn)）title('生活類(lèi)');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,

6、d2,'g*-')legend('原始數(shù)據(jù)','指數(shù)增長(zhǎng)模型','阻滯增長(zhǎng)模型',2)xlabel 時(shí)間段ylabel 公眾號(hào)總量（萬(wàn)）title('消遣類(lèi)');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('原始數(shù)據(jù)','指數(shù)增長(zhǎng)模型','阻

7、滯增長(zhǎng)模型',2)xlabel 時(shí)間段ylabel 公眾號(hào)總量（萬(wàn)）title('其他');參數(shù)資訊類(lèi)生活類(lèi)消遣類(lèi)其他類(lèi)公眾號(hào)總量程序代碼：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=0.40,0.97,2.31,4.45,7.63,10.1

8、1,19.86,33.44,38.03,75.07,112.08,152.39,226.55'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=0.54,1.18,1.98,5.06,8.77,15.65,23.89,36.63,37.17,53.98,73.16,123.31,159.78'st_ = 500 30 0.2 ;ft_ = fittype('a0/(1+b0*exp(-k0*(x-1)',. 'dependent'

9、;,'y','independent','x',. 'coefficients','a0', 'b0','k0');cf_ = fit(x,y,ft_,'Startpoint',st_)plot(cf_,'fit',0.95);hold on,plot(x,y,'ro')f1t_ = fittype('a1/(1+b1*exp(-k1*(x-1)',. 'dependent','b',&#

10、39;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','independen

11、t','x',. 'coefficients','a2', 'b2','k2');c2f_ = 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&#