SumX = N * ( N - 1 ) * 1/2; SumY = Summation( Close, N) ;//求和
for i = 0 to N-1 { SumXY = SumXY + i * Close[i] ; //close[i]就是ref(c,i) SumXX = SumXX + i * i ; SumYY = SumYY + Close[i] * Close[i] ; } |
sumxy
sumxx
sumyy的初始值是?
不好意思啊,复制错了,抱歉
n:=30;
sumx:=n*(n-1)/2;
sumy:=sum(c,n);
variable:sumxx[n]=0,sumyy[30]=0,sumxy[30]=0;
r1:=ref(c,1);
for i=2 to n do begin
sumxy[i]:=sumxy[i-1]+i*r1;
sumxx[i]:=sumxx[i-1]+i*i;
sumyy[i]:=sumyy[i]+r1*r1;
end
r2:=(sumxy-n*(sumx/n))/sqrt((sumxx-sumx*sumx/n)*(sumyy-sumy*sumy/n));