intersection of 2 graphs

[utopian_sorceror]

I plotted 2 sets of data on the same set of axes.. now I need to find the
intersection point of the two trendlines. Please let me know how I can do
this (if I can)?

This is probably very trivial.. really appreciate all the help.

Thanks!

 

[Andy Pope]

Hi,

Have a look at this explanation.
http://www.andypope.info/charts/intersection.htm

Cheers
Andy

 

[utopian_sorceror]

thanks for the link.. your excel worksheet says that your intersections
formula is evaluating to an error though. apparently, excel doesn't
understand what is "lineb", could you explain further pls?

also, would this method work when I'm not using line segments between data
points, but an exponential trendline for the entire set?

if it helps, i'm trying to do load line analysis of a resistor and a diode..
so I have this exponential looking graph and this straight line and I need to
find where they intersect

thanks so much! really appreciate.

 

[Andy Pope]

Hi,

LineB is a named range. In the example check under the menu Insert >
Names > Define.

If you want to do intersects of a trend line then you will need to
generate some x and y values for the trendline and use those.
Use LINEST for this purpose
http://www.stfx.ca/people/blie ngme/ExcelTips/Polynomial.htm

Cheers
Andy

 

[utopian_sorceror]

ok i think i get it thanks so much again.. i'll go fiddle with my data...

 

[tinga]

hi,
I have the same problem. I tried to use the function in the example but it
is not working. can you explain more please.

 

[Andy Pope]

Hi,

There is not a lot more to explain.

The user function will not work if you do not have any or all of the
following,

the code for the user defined function
macros enabled
the named ranges used in the formula specified

If you need more help you will need to explain exactly what *your* problem
is as the post you tagged on to has 2 problems/solutions in it.

Cheers
Andy