Faster For-Next Loop?

In the function below I have a For-Next loop that loops though a range
of cells. Would it be any faster to read the range into an array and
loop through the array?

Function InvDistanceWtd(x, y, xdata as Range, ydata as Range, zdata as
Range, power)
N = Application.Count(xdata)
For i = 1 To N
D = Sqr((x - xdata(i, 1)) ^ 2 + (y - ydata(i, 1)) ^ 2)
SumZoDn = SumZoDn + data(i, 1) / D ^ Power
SumIDn = SumIDn + 1 / D ^ Power
Next i
InvDistanceWtd = SumZoDn / SumIDn
End Function

Depending on the size of your range, but in general: a LOT faster!
The arrays in my functions are generally 120 elements (actuarial tables);
difference in the order of 10 times faster.

<dgp@dodgeit.com> wrote in message
news:1105123565.180885.268380@z14g2000cwz.googlegroups.com...
> In the function below I have a For-Next loop that loops though a range
> of cells. Would it be any faster to read the range into an array and
> loop through the array?
>
> Function InvDistanceWtd(x, y, xdata as Range, ydata as Range, zdata as
> Range, power)
> N = Application.Count(xdata)
> For i = 1 To N
> D = Sqr((x - xdata(i, 1)) ^ 2 + (y - ydata(i, 1)) ^ 2)
> SumZoDn = SumZoDn + data(i, 1) / D ^ Power
> SumIDn = SumIDn + 1 / D ^ Power
> Next i
> InvDistanceWtd = SumZoDn / SumIDn
> End Function
>

Hello. You pass "zdata" to your function, but I don't see it used. Is
there a typo?

--
Dana DeLouis
Win XP & Office 2003


<dgp@dodgeit.com> wrote in message
news:1105123565.180885.268380@z14g2000cwz.googlegroups.com...
> In the function below I have a For-Next loop that loops though a range
> of cells. Would it be any faster to read the range into an array and
> loop through the array?
>
> Function InvDistanceWtd(x, y, xdata as Range, ydata as Range, zdata as
> Range, power)
> N = Application.Count(xdata)
> For i = 1 To N
> D = Sqr((x - xdata(i, 1)) ^ 2 + (y - ydata(i, 1)) ^ 2)
> SumZoDn = SumZoDn + data(i, 1) / D ^ Power
> SumIDn = SumIDn + 1 / D ^ Power
> Next i
> InvDistanceWtd = SumZoDn / SumIDn
> End Function
>

Yes, I was in the process of renaming the range variable data (used in
line 5) to zdata.

Dana DeLouis wrote:
> Hello. You pass "zdata" to your function, but I don't see it used.
Is
> there a typo?
>
> --
> Dana DeLouis
> Win XP & Office 2003
>
>
> <dgp@dodgeit.com> wrote in message
> news:1105123565.180885.268380@z14g2000cwz.googlegroups.com...
> > In the function below I have a For-Next loop that loops though a
range
> > of cells. Would it be any faster to read the range into an array
and
> > loop through the array?
> >
> > Function InvDistanceWtd(x, y, xdata as Range, ydata as Range, zdata
as
> > Range, power)
> > N = Application.Count(xdata)
> > For i = 1 To N
> > D = Sqr((x - xdata(i, 1)) ^ 2 + (y - ydata(i, 1)) ^ 2)
> > SumZoDn = SumZoDn + data(i, 1) / D ^ Power
> > SumIDn = SumIDn + 1 / D ^ Power
> > Next i
> > InvDistanceWtd = SumZoDn / SumIDn
> > End Function
> >