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peterh1
4 Posts |
 Posted - 12/06/2008 : 6:56:34 PM
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Hi
I have a question in regards to making 3d plots.
As i understand in order to make a 3D surface plot i need to have a matrix.
I have a excel spead sheet matrix. where in the first row are my X values and in the first column are my Y values and the space in between contains the Z values. X and Y are differtn is is not a quadratic matrix in fact it is circular.
The x values are a function of the y values (it is basicaly a circle) with Y=(r^2-x^2)^0.5.
Now i would like to plot this in 3D.
How do i do this?
Can i just copy paste the excel spear sheet into Origin as a matrix? as i did here. How do i tell Origin that the first row is X and the first column is y? and draw the 3D graph.
thank you for your help
Peter
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Deanna
China
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Posted - 12/08/2008 : 01:48:56 AM
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Hi Peter,
Plotting from matrix utilizes the X and Y coordinates of the matrix. Therefore, we should perform a little bit setting to the matrix to make your X Y values as the coordinates of the matrix.
I suggest doing the following:
1. Make your matrix active.
2. Select Matrix: Convert to Worksheet from the main menu to open the dilaog of m2w.
3. In this dialog, customize the settings as follows:
4. After you click OK, you should have a new workbook.
5. Make sure this workbook is active. Select Worksheet: Convert to Matrix: Direct from the main menu. The dialog of the w2m should be opened.
6. In this dialog, select X across Columns with the Data Format drop-down list. Select First Row with the X Values in drop-down list. Also, select the Y Values in First Column check box. Finally, click OK.
7. This should generate a matrix. Select View: Show XY from the menu. You can see your X Y values have been used to set the coordinates. Now you can try to create a 3D plot with it.
Deanna
OriginLab Technical Services |
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peterh1
4 Posts |
Posted - 12/10/2008 : 09:36:39 AM
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Dear Danna
Thank you for your help.
If i try to convert the created worksheet back to a matrix i recieve the following massage:
Your Y data are not evenly spaced, it has fluctuation of 569.23%.
Please try changing the tolerance setting.
If the fluctuations are very large, you should transform your
data to XYZ column format and then use the matrix gridding tool.
do you know what i did wrong?
thanks
Peter
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greg
USA
1378 Posts |
Posted - 12/10/2008 : 10:34:50 AM
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A Matrix in Origin must be linearly mapped - that is, the difference between X values or Y values must be a constant. So if your X or Y values are not linear, do the following (assuming Origin 8 SR3 or later):
Choose Worksheet : Convert to XYZ
This creates a new worksheet with the data rearranged by XYZ triplets. You can plot this directly as an XYZ Contour which should pick up your circular outline automatically.
Select the Z column in this new worksheet and choose Worksheet : Convert to Matrix : XYZ Gridding
Origin provides various gridding algorithms to convert daya with non-linear XY spacing into a linearly mapped matrix. With such a matrix, you can plot Surfaces as well as Contours. |
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Ranteng
1 Posts |
Posted - 12/15/2010 : 12:26:32 PM
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quote:
Originally posted by greg
A Matrix in Origin must be linearly mapped - that is, the difference between X values or Y values must be a constant. So if your X or Y values are not linear, do the following (assuming Origin 8 SR3 or later):
I've got a situation where my data comes in in in triplets but the spacing of the X and Y parameters are logarithmically. The data is necessarily denser at the lower X and Y values. Is there a way to create surface plots or to expand the data to simulate linearity without loss of resolution? |
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easwar
USA
1964 Posts |
Posted - 12/16/2010 : 09:39:15 AM
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Hi,
With data arranged as XYZ, currently you can only make contour plot directly from such data. In order to make a surface plot, the data has to be either in a matrix or has to be arranged "like a matrix" in a worksheet. This second option is a new feature, called Virtual Matrix, in version 8.5. The first option of converting to matrix will not work for you as your data is logarithmically spaced.
Is it possible to rearrange your data as an mxn array in a worksheet? Then with 8.5 you can make surface plots.
Perhaps you can send us your data and we could take a further look. Use the "Send File to Tech Support" link at the top right side of this page, and please refer to this forum post in your message.
Easwar
OriginLab |
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amela1908
4 Posts |
Posted - 06/14/2011 : 11:02:36 AM
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Hello,
I would appreciate very much if someone could help me.
I have a problem with making a 3D surface plot out of my data.
Here are my data:
x y z
0,21 1,47 0,2
0,34 1,3 0,3
0,83 2,5 0,15
0,86 3 0,15
0,94 1,59 0,59
8,61 0,36 0,74
12,27 0,84 0,1
25,3 0,74 0,5
That are 8 points with (x,y,z) coordinates which should be on the plot. The thing is I would like to circle the surface which they surround but I don´t know how to do it.
Can someone please help me
And is it possible to label the data points on a 3D plot in Origin 8.5 version?
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Hideo Fujii
USA
1582 Posts |
Posted - 06/14/2011 : 4:17:00 PM
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Hi Amela,
Although you can convert your XYZ worksheet data to a matrix by "Worksheet: Convert to Matrix: XYZ Gridding" menu in Origin 8.5, since your most data are almost on (parallel to) either XZ plane or YZ plane, the conversion result (by any random gridding method for interpolation) may be unreliable. Still, you can make a surface plot from the result matrix if you satisfy the conversion result (In the Gridding tool, you can show the preview plot of the result in the right panel of the tool.)
I bet that the best you can do is to plot a contour DIRECTLY from a XYZ worksheet ("Plot: Contour: ColorFill" menu) in Origin 8.5, which doesn't involve the gridding conversion.
I hope this gives you some insight.
--Hideo Fujii
OriginLab |
Edited by - Hideo Fujii on 06/14/2011 4:17:27 PM |
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amela1908
4 Posts |
Posted - 06/15/2011 : 03:42:52 AM
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Hello,
first of all thank you for your quick reply.
Unfortunately, I am still having difficuties with making a plot.
As you already said, the results after converting xyz data to matrix are unreliable, they do not represent the real points at all.
I also tried making the plot directly from my data: plot -> contour -> color fill, but then I get a 2D plot (without "z" coordinate).
If you have any more suggestions, ideas, etc. please feel free to share it with me ´cause I don´t have a clue what else I could try! I am starting to think that it is not possible to do it, although it is seems like a very simple thing.
Thank you once again.
Regards
Amela |
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Hideo Fujii
USA
1582 Posts |
Posted - 06/15/2011 : 10:49:18 AM
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Hi Amela,
Considering information loss-less or artifact-less presentation from such sparse data, how about the 3D Scatter plot, or Bubble and/or Color-mapped plot? In the later case, the symbol color and/or size represent the Z value.
--Hideo Fujii
OriginLab |
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3D matrix and plot question