Points in between Data Series

[Guest]

I'm using an xy scatter chart, to do grain size analysis, what I need to
know is how do I find out the value in between data points, for example I
would like to know the value of where my data series line crosses at 60% what
is my x value.

I apologize for any confusion, I'm not sure how to properly ask this
question.

D

 

[MrShorty]

This isn't the kind of thing that Excel has built into it, but i
certainly is capable of the calculations necessary. Do you just have
table of data or do you have an analytic function [y=f(x)] for the grai
size that you could use to calculate x at y=.6?

If you have the function, then it would be easy enough to solve th
equation for y=.6 either analytically or numerically (using Solver/Goa
seek).

If you don't have the function, you could curve fit the tabulated dat
to a reasonable function and then use that to estimate x at y=0.6.

You could also use an interpolation routine (linear interpolation is b
far the easiest to implement) to estimate x at y=0.6. Excel doesn'
have a built in interpolation routine, but you could build one eithe
with worksheet functions or in VBA.

If all else fails, you could visually pick the value off of the chart

 

[Ed Ferrero]

Hi Broken man,

If you just want linear interpolation, download 'Intercept Vertical Lines'
from http://edferrero.m6.net/charting.aspx

Ed Ferrero
http://edferrero.m6.net/