Interpolation Visual Basic Macro!!!!

[L. Tucker]

I have two columns of data (let's call them x and y). Now
I have a x-value in another cell somewhere in the range of
the x data and I want an interpolated y-value as an
output. Please help! I'm sure there is a visual basic
macro that can be written for this, but cannot figure out
how to do it. Could anyone please help?!?!? Thanks so much.

 

[Jerry W. Lewis]

Agreed that more info is needed (type of interpolation, is data sorted,
etc.), but regression is not interpolation. Interpolation passes
through the data points; regression passes near them, but does not
necessarily pass through any data points.

Jerry

 

[L. Tucker]

Sorry for the lack of info... To be more specific, I have
one column of temperatures in ascending order (i.e. 20-700
deg C, in increments of ~50 deg C) and another column(s)
of corresponding material data for each temperature point.
Now I want to output data for a specific temp that falls
w/i the data that I have... let's say for 48.5 deg C for
example. I only need a linear interpolation function or
macro. Can anyone please help me with this? Thanks so much
for your replys so far.
Leslie

 

[Jerry W. Lewis]

For concreteness, I will assume that the temperatures are in A1:A15, the
material data are in B1:B15, and that D2 contains the specific
temperature for which you want to interpolate a value.

=FORECAST(D2,OFFSET($B$1:$B$15,MATCH(D2,$A$1:$A$15)-1,0,2),OFFSET($A$1:$A$15,MATCH(D2,$A$1:$A$15)-1,0,2))

should do the trick. It depends critically on the temperatures being in
ascending order, and there being no blank cells in either the
temperature or the material data ranges.

Jerry