When a 3D wire Surface plot is created the number and size of the wire grid is determined by the size of the matrix, and the Z values
[size=2]When a 3D wire Surface plot is created the number and size of the wire grid is determined by the size of the matrix. First make sure that speed mode is disabled. (Format: Layer: Size/Speed Tab). If you have a 10 X 10 Matrix, there will be 10 Grid Lines. A 32 X 32 Matrix would have 32 grid lines. The boxes that are created represent the surface between the Matrix values, and need to be stretched to represent the Z data from each Matrix cell in a perspective view. If you rotate the image to look straight down, the grids will be square.
In Origin it is not possible to create any 3D graphs with other than a linear X and Y scale. It is possible to set the Z-axis to a log scale. Because you only want to display the log scale lines without regard to the actual values of the data, it is possible to create a second layer with a log scale and superimpose it onto the data, which is in the first layer. Note: This is further complicated by the fact that your X data goes negative. There is no way to define a log scale with negative numbers.
1. From your matrix data create two identical 3D surface plots.
2. From the Origin menu bar select Edit: Merge all graph windows. You will want to save your old graphs when asked.
3. Set both the number of rows and columns as 1 and use the defaults for the spacing in the next dialog box.
You can now minimize the two original graphs and drag the new graph larger.
4. Double-click on the layer 2 Icon in the upper left of the new graph window.
5. Move your Matrix data in layer 2 from the "layer contents" column back to the "available data" column. This removes the data from this second layer so you can re-scale the axis without affecting the actual data. It also removes the lock that prevents you from selecting the log scale for the x-axis dialog box. Close the dialog box by clicking on OK.
6. With layer 2 active (the layer 2 Icon is depressed) select from the main Origin menu Format: Layer. On the "Planes" tab turn off all planes. On the "Size and Speed" tab turn off the "Speed Mode".
7. Select Format: Axis: X Axis and set the scale from 1 to 100000, Type to Log10 and Rescale to Manual.
8. Select the "Grid Lines" tab and turn off the grid lines for the Horizontal and Z-axes. Click OK.
At this point you will probably want to clean up layer 1.
9. Make layer one active and from the main Origin menu select Format: Layer. One the display tab you can turn off the X, Y, and Z axes. You may also want to turn off the Layer 1 back-planes from the "Planes" tab. When you are done, click OK.
I have placed a copy of an example of this type of graph on the FTP site Igor.microcal.com. If you are using an FTP program, log on with anonymous as the username and your email address as the password. The file is in the Public directory and the filename is 3Dlogscale.opj
If you are using Netscape or MS Internet explorer, the following link will take you directly to the Origin project for downloading.
ftp://igor.microcal.com/pub/3Dlogscale.OPJ
If you need additional help with this graph please contact OriginLab technical support.
XY grid lines: regular spacing->log spacing??
Posted - 04/08/2001 : 7:26:24 PM
