Problem analyzing my data

[Guest]

I am having a problem analyzing some data and I think my problem may have to
do with not knowing enough about excel. I have one spreadsheet where i set
up a plot of Resistance to Voltage. Now in another spreadsheet I have a
completely different set of measurements for Voltage and I want to find the
corresponding Resistance, using the plot from the first spreadsheet. How do
i do this? I am pulling my hair out over here! I would go through my data
points and do it by hand but I have over 900 data points. Any help would be
appreciated.

 

[Zack Barresse]

Hello Amanda,

Without seeing your data I'd say you could either use a combination
INDEX/MATCH type function or (if data structure is correct) a VLOOKUP or
LOOKUP type formula. I'd recommend reading up on each of the formulas, the
Help files are decent on them. Post back if you need any help with them.

 

[vandenberg p]

Hello:

I do not know anything about volts and resistence other than what I have
just read here: (and I am not sure I understand all of it)

http://www.allaboutcircuits.com/vol_1/chpt_2/1.html

According to this site if you hold amps constant the relationship between
resistance (measure in ohms) and voltage is linear. Therefore just
plot the data on an xy scatter and then right click the series and choose
trendline, linear and on options select display equation and r^2. You
can then use this equation to estimate the Ohms for your other data.

If amps are constant you should get a perfect fit (r^2=1), if they are not
you will not get a perfect fit. The more your amps vary the poorer will be
fit. But in any case the relationship between ohms and volts is still linear
and variation is cause by the third factor(amps).


Pieter Vandenberg

: I am having a problem analyzing some data and I think my problem may have to
: do with not knowing enough about excel. I have one spreadsheet where i set
: up a plot of Resistance to Voltage. Now in another spreadsheet I have a
: completely different set of measurements for Voltage and I want to find the
: corresponding Resistance, using the plot from the first spreadsheet. How do
: i do this? I am pulling my hair out over here! I would go through my data
: points and do it by hand but I have over 900 data points. Any help would be
: appreciated.