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Text File  |  1995-04-02  |  440 b   |  11 lines
  1. #  fit([x1,x2,...], [y1,y2,...]) fits [y1,y2,...] into a straight line of
  2. #  a+b*x
  3. #  e.g. fit([1,2,3],[1,3/2,2]) gives 1/2+1/2*x
  4.  
  5. fit(xlist_,ylist_) := block(xmean:=average(xlist), ymean:=average(ylist),
  6.   length:=length(xlist),
  7.   lxx:=sum((member(xlist,j)-xmean)^2, j,1,length,1),
  8.   lxy:=sum((member(xlist,j)-xmean)*(member(ylist,j)-ymean), j,1,length,1),
  9.   ymean-lxy/lxx*xmean+lxy/lxx*x,
  10.   local(p,xmean,ymean,lxx,lxy,length))
  11.