using two graphs to draw a third.

[labview1958]

I have two graphs in excel. One graph has the values (1,3), (3,5), (5,
9), (7, 13) etc. The second graph has the values (2,3), (4,7), (6, 11),
(8, 19) etc. I would like to draw a third graph using the two graphs
like (1, y1/y2), (2, y1/y2), (3, y1/y2), (4, y1/y2) etc. Here y1 is the
value from graph 1 and y2 the corresponding value from graph 2. Now, I
am doing using a long method. First find the equation for graph 1 and
then find the y values for x=1,2,3 etc. The technique is repeated for
graph 2. Then I divide the values and plot the graph. It is tedious.
Is there a faster way?

 

[labview1958]

Anyone can help?

 

[labview1958]

anyone can offer any help?

 

[labview1958]

Anyone out there can help?

 

[Jon Peltier]

You feel like explaining what you want?

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


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[labview1958]

Graph 1.(measurement)
(1,3), (3,5), (5, 9), (7, 13)

Graph 2.(measurement)
(2,3), (4,7), (6, 11), (8, 19)


Graph 3.(calculation)
(1, y1/y2), (2, y1/y2), (3, y1/y2), (4, y1/y2)

where y1 and y2 is obtained by first drawing a trendline, finding it's
equation and then substituting the x value to find the corresponding y
value. The two y values corresponding to a particular x is then found.
The ratio of the two y values is then calculated. Finally a third graph
is drawn.

The whole process is tedious. Is there a simpler way?

 

[Jon Peltier]

You can find routines in the archives or on the internet to calculate
piecewise interpolated values. Use these to calculate the Y1 values and Y2
values, then compute your ratios. Once you set up one worksheet with the
formulas, you can reuse it for additional data sets.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"labview1958" <[email protected]>
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[labview1958]

Each set of two graphs is different from the next set. So I have new
equations all the time. Is there a better way?

 

[Jon Peltier]

Is the data laid out the same? If so, you can just paste the new values over
the old in the template I've described, and the parameters will be
recomputed. If not, can you make it similar, to minimize manual rework?

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"labview1958" <[email protected]>
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