Brooke,
The MS slope formula is for the least square line thru the last 14 points. For y = a + b*x, the LS slope, b, is given by
b = (S*Sxy -Sx*Sy)/(S*Sxx -Sx*Sx), where S = # of Points, Sx = sum(x), etc. This translates to the scan given below for R2.
Bob
--------
output = "slope.lst";
issuetype common;
Daystoload = 50; //needed for R2 bug!!!
integer i, S, Sx, Sxx;
float b, Sxy, Sy;
S := 14;
Sx := 0;
Sxx := 0;
Sxy := 0;
Sy := 0;
for i = 1 - S to 0 do
Sx := Sx + i;
Sy := Sy + close(i); //kills println wo d2ld
Sxx := Sxx + i*i;
Sxy := Sxy + i*close(i); //kills println wo d2ld
//Sxy := Sxy + i*close(0);
next i;
b := (S*Sxy - Sx*Sy)/(S*Sxx - Sx*Sx);
println symbol,",",close(0):8:2,",",b:8:2; |
