基于matlab的函數(shù)逼近

1、精選優(yōu)質(zhì)文檔-傾情為你奉上精選優(yōu)質(zhì)文檔-傾情為你奉上專心-專注-專業(yè)專心-專注-專業(yè)精選優(yōu)質(zhì)文檔-傾情為你奉上專心-專注-專業(yè)1 設(shè)計一個在U=-1,1-1,1上的模糊系統(tǒng)，使其以精度=0.1一致地逼近函數(shù),并進(jìn)行matlab仿真。解：根據(jù)題目要求，知，L=2，T=0.1，可取h=0.05,N=L/h+1=21程序如下所示：%Fuzzy approaching clear all; close all; T=0.1; x1=-1:T:1; x2=-1:T:1; L=2; h=0.05; N=L/h+1; for i=1:1:N %N MF for j=1:1:N e1(i)=-1+L/(N-1

2、)*(i-1); e2(j)=-1+L/(N-1)*(j-1); gx(i,j)=sin(e1(i)*pi)+cos(e2(j)*pi)+sin(e1(i)*pi)*cos(e2(j)*pi)end end df=zeros(L/T+1,L/T+1); cf=zeros(L/T+1,L/T+1); for m=1:1:N %u1 change from 1 to N if m=1 u1=trimf(x1,-1,-1,-1+L/(N-1); %First u1 elseif m=N u1=trimf(x1,1-L/(N-1),1,1); %Last u1 else u1=trimf(x1,e1(

3、m-1),e1(m),e1(m+1); end figure(1); hold on; plot(x1,u1); xlabel(x1);ylabel(Membership function); for n=1:1:N %u2 change from 1 to N if n=1 u2=trimf(x2,-1,-1,-1+L/(N-1); %First u2 elseif n=N u2=trimf(x2,1-L/(N-1),1,1); %Last u2 else u2=trimf(x2,e2(n-1),e2(n),e2(n+1); end figure(2); hold on; plot(x2,u

4、2); xlabel(x2);ylabel(Membership function); for i=1:1:L/T+1 for j=1:1:L/T+1 d=df(i,j)+u1(i)*u2(j); df(i,j)=d; c=cf(i,j)+gx(m,n)*u1(i)*u2(j); cf(i,j)=c; end end end end % for i=1:1:L/T+1 for j=1:1:L/T+1 f(i,j)=cf(i,j)/df(i,j); y(i,j)=sin(x1(i)*pi)+cos(x2(j)*pi)+sin(x1(i)*pi)*cos(x2(j)*pi)end end figure(3); subplot(211); surf(x1,x2,f); title(f(x); subplot(212); surf(x1,x2,y); title(g(x); figure(4); surf(x1,x2,f-y); title(Approach