| T O P I C R E V I E W |
| KMnO4aq |
Posted - 10/27/2011 : 11:20:29 AM
Origin Ver. and Service Release (Select Help-->About Origin): 8.5
Operating System: Windows 7 run on parallels desktop
So, what I'm trying to do should be easy, but it is proving to be quite annoying. I have two graphs plotted on the same layer. I am trying to divide the y values of one curve by the Y values of another curve.
The data has two different sets of X values (that run over the same scale but are not at the same increments) so I cannot simply do this in the spreadsheet.
Any suggestions on how I can get Origin to do this for me? |
| 1 L A T E S T R E P L I E S (Newest First) |
| Hideo Fujii |
Posted - 10/27/2011 : 4:59:42 PM
Hi,
Have you tried "Analysis: Mathematics: Simple Curve Math" menu?
Here you can select "Divide" operator, operand=Reference Data. (You may want to choose <New>" if you want to preserve the original curve.)
Or, if you want to control more details as lengthy, you can run the interpolation to get the corresponding X values for both curves. Here is one way to do for the data such that, let's say that you have A(X)B(Y)C(X)D(Y) columns:
1) Highlight col(A), and choose "Analysis: Mathematics: Interpolate/Extrapolate" menu.
2) Turn OFF "Auto" check boxes for Number of Points, X Min, and X Max,
and enter appropriate values, say 101, 0.0, and 1.0, respectively.
This creates an interpolated Y col(E) with initial=0 interval=0.01 .
3) Do the same 2) for col(D) with same settings to create col(F).
4) Add a column, col(G), and open Set Column Values tool, and enter the following formulae:
col(E)/col(F)
[in Before Formula Scripts]:
range cE=col(E);
range cG=col(G);
cG.xinit=cE.xinit;
cG.xinc=cE.xinc;
Here the last two commands copy the initial value and the interval of column E to this new column G.
I hope this is helpful.
--Hideo Fujii
OriginLab |
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