jxtiqu.m

一个处理化学数据的MATLAB程序

function YY=jxtiqu2(YY,X)

eps=1.0e-5;
cvalue=1.0;
XJD=X(1:300);             %X的前300个数据
YJD=YY(1:300)';           %YY的前300个数据的转置
P=polyfit(XJD,YJD,2);     %拟合出一条二次曲线(函数拟合)
tendency=polyval(P,X');   %多项式在x处的值
%plot(YY,'b')
%hold on
%plot(tendency,'k')
%plot(YY-tendency,'r')
YY=YY-tendency;
%hold off
%pause
nonsignalvalue=0.0;
while cvalue>=eps
index=find(YY<=nonsignalvalue);     %返回满足条件的YY的序号
XJD=X(index);                     %再次拟合,直到
YJD=YY(index)';
P=polyfit(XJD,YJD,2);
tendency=polyval(P,X');
%plot(YY,'b')
%hold on
%plot(tendency,'k')
%plot(YY-tendency,'r')
YY=YY-tendency;
cvalue=abs(min(YY));%also well!
%cvalue=max(abs(tendency));%also well!
%hold off
%pause
end