| T O P I C R E V I E W |
| 00S |
Posted - 04/20/2009 : 05:15:01 AM
Origin Ver. and Service Release: 7.5G SR6
Operating System: Win XP
Dear Origin users,
I would like to measure a volume which is an irregular shape immerged into a plane or spherical surface (wear scar of a "pin on disk" experiment). I have a z=f(x,y)-matrix of the wear scar and the remaining surrounding original surface.
If I can compute a new matrix which just has the original surface (plane, sphere), I would be able to substract it from my actual data and get the wear scar surface being leveled at z=0. Then I could just add up my delta-matrix values and and multiply with dx*dy and have my volume.
My problems are:
1) The surounding surface is not flat but slightly rough, therefore I cannot set up a plane-function with any 3 points or a sphere-function with any 4 points. I need something to have a good fit of the plane/sphere to the surrounding area.
(Is there a way I can use the non-linear curve fit function for z=f(x,y) functions?)
2) Can I substract and add different matrices in origin? How do I add up all values?
(= Is there a way around learning the script laguage;-) )
If anybody has an idea how to solve this problem, maybe even using a completly different apporach, I highly appreciate any input.
I have not worked too much with Origin yet but would get deeper into it if I know what I have to look for.
Thanks in advance,
Stefan
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| 1 L A T E S T R E P L I E S (Newest First) |
| greg |
Posted - 04/23/2009 : 4:25:00 PM
You can do multi-dimensional fitting in Origin as explained here:
http://www.originlab.com/www/support/resultstech.aspx?ID=57&language=English&Version=All
You will have to come up with a function you think appropriate and define it in the fitter.
Be sure to use Same X as Data. The fitter does not produce a matrix, instead it creates datasets.
You can add and subtract matrices provided they have the same dimensions. So if you have two matrices (Matrix1 and Matrix2) that are 120 columns by 80 rows, then you can create a third (Matrix3) that is also 120 by 80 and execute this in the script window:
Matrix3 = Matrix1 - Matrix2.
If you don't need the originals you can also just do
Matrix1 = Matrix1 - Matrix2
or
Matrix1 -= Matrix2
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