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premiumxy
17 Posts |
 Posted - 04/01/2011 : 10:59:36 AM
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Origin Ver. and Service Release (Select Help-->About Origin): 8.1 pro
Operating System: Win XP
Hello,
I have the following issues fitting 2D surfaces:
My data (XYZ) is arranged in a matrix and it contains several peaks. I would like to find the position of these peaks by fitting them with the 2DGauss function.
Giving the correct data range for this analysis is crucial. I realized the following:
1) In a matrix surface plot, the data selection tool does not work
2) Converting the data to a XYZ worksheet help a little bit.
a) Selecting a data range area (rectangle) only limits the data by taking a start and end column. This leads to range limited in the X coordinate, but still spreading over the full Y range --> Peaks with the same X coordinate are not distinguishable
b) Using a free-form data selection tool creates multiple ranges (one range for each column) --> looks good. Unfortunately, in the surface fitting only Range1 can be chosen (which corresponds to ONE X-Value, and the corresponding Y values) --> no fits possible
My question: Can this issue solved easily? Or is a complicated workaround necessary (like using the Worksheet Data selection tool and some selection functions [for non-rectangular data range areas quite complicated], creating new worksheets and fitting the whole range).
I am glad for any help!
Stefan |
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greg
USA
1378 Posts |
Posted - 04/01/2011 : 2:07:45 PM
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You should use the Region of Interest Tools - which should be turned on automatically if a matrix is active AND it is in Image view mode.
It can be toggled on/off with Ctrl+Shift+T or selected from the Tools menu.
In ROI mode, the rectangle tool is green.
Click it.
Now in the matrix image you can drag a rectangle around the peak you are interested in.
Use the sizing handles to move it into the best position.
Now right-click anywhere within the rectangle and choose Create New.
This creates a new matrix from the selected region - correctly mapped for XY.
You can return to the original matrix, click where the rectangle should be, and drag it to the next peak and repeat. (If you 'lost it', you can use the pointer tool to drag-select the whole image which will 'find' it again.)
Pick one of the new matrices and do a surface fit. Now you should be able to quickly go through the remaining new matrices using the <Last Used> theme available in the menu.
FYI : Our next version will have replica for surface fit which will find peaks for you and fit them all simultaneously. |
Edited by - greg on 04/01/2011 2:10:39 PM |
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premiumxy
17 Posts |
Posted - 04/04/2011 : 12:47:30 PM
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Thank you Greg, sounds like a reasonable solution. However, when I try to copy the region of interest, a message pops up:
"support active matrix window only"
Do you know how to solve this issue? My graph is a surface plot of a matrix, so it should be fine.
As an additional questions: Are there any other shapes than rectangles possible, e.g. freehand? I guess if yes, this will only work in a XYZ surface plot?!
Thanks, Stefan |
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surface fitting - data range?