Hi all


I have written a Function to calculate a hypobolic function for a
given range of data ( in this case 5 samples). Is there a way I can
change this to accept any number of samples (I would like to accept at
least 15)? I had thought that a function using arrays might do it,
but unfortuanatly the theory behind arrays is doing my head in! here
is a copy of the function code wich I have achieved by brute force (
in summary its a funtion to add the sums of various combinations of x
and y)

Thanks for any help

Ian Mangelsdorf

Function Sw_hyp(P1, P2, p3, p4, p5, sw1, sw2, sw3, sw4, sw5, Pc_hyp)
y1 = P1
y2 = P2
y3 = p3
y4 = p4
y5 = p5
x1 = sw1
x2 = sw2
x3 = sw3
x4 = sw4
x5 = sw5



Sumx = x1 + x2 + x3 + x4 + x5
Sumy = y1 + y2 + y3 + y4 + y5
Sumx2 = x1 ^ 2 + x2 ^ 2 + x3 ^ 2 + x4 ^ 2 + x5 ^ 2
Sumy2 = y1 ^ 2 + y2 ^ 2 + y3 ^ 2 + y4 ^ 2 + y5 ^ 2


Sumxy = (x1 * y1) + (x2 * y2) + (x3 * y3) + (x4 * y4) + (x5 * y5)


'calculate x squared y's

xSy1 = x1 ^ 2 * y1
xSy2 = x2 ^ 2 * y2
xSy3 = x3 ^ 2 * y3
xSy4 = x4 ^ 2 * y4
xSy5 = x5 ^ 2 * y5

Sumx2y = xSy1 + xSy2 + xSy3 + xSy4 + xSy5

'calculate x y squared

xyS1 = y1 ^ 2 * x1
xyS2 = y2 ^ 2 * x2
xyS3 = y3 ^ 2 * x3
xyS4 = y4 ^ 2 * x4
xyS5 = y5 ^ 2 * x5

Sumxy2 = xyS1 + xyS2 + xyS3 + xyS4 + xyS5


'calculate x sq y sq

xSyS1 = y1 ^ 2 * x1 ^ 2
xSyS2 = y2 ^ 2 * x2 ^ 2
xSyS3 = y3 ^ 2 * x3 ^ 2
xSyS4 = y4 ^ 2 * x4 ^ 2
xSyS5 = y5 ^ 2 * x5 ^ 2


Sumx2y2 = xSyS1 + xSyS2 + xSyS3 + xSyS4 + xSyS5


number1 = Sumx2 * (Sumxy * Sumxy2 - Sumy * Sumx2y2) + Sumxy * (Sumx *
Sumx2y2 - Sumxy * Sumx2y) + Sumx2y * (Sumy * Sumx2y - Sumx * Sumxy2)
number2 = samples * (Sumx2y * Sumxy2 - Sumxy * Sumx2y2) + Sumx * (Sumy
* Sumx2y2 - Sumxy * Sumxy2) + Sumxy * (Sumxy ^ 2 - Sumy * Sumx2y)
number3 = samples * (Sumx2 * Sumxy2 - Sumxy * Sumx2y) + Sumx * (Sumy *
Sumx2y - Sumx * Sumxy2) + Sumxy * (Sumx * Sumxy - Sumy * Sumx2)
denomin = samples * (Sumx2y ^ 2 - Sumx2 * Sumx2y2) + Sumx * (Sumx *
Sumx2y2 - Sumxy * Sumx2y) + Sumxy * (Sumxy * Sumx2 - Sumx * Sumx2y)


a = number1 / denomin
b = number2 / denomin
C = number3 / denomin



Sw_hyp = (a - Pc_hyp) / (C * Pc_hyp - b)

End Function