Navigation:  Getting Started > Getting Started with XYZ Surface Plots >

Getting Started with XYZ Surface Plots - Data From a Disk File

Print this Topic Previous pageReturn to chapter overviewNext page

For tables of Z values, see below.

For 3 columns containing X,Y,Z data

Select the Open command on the File menu. Select file type K on the Select File Type dialog:

This format is an ASCII text file containing randomly-spaced 3D points, one X,Y,Z triplet per line. Comma-separated values (CSV) files produced by Microsoft Excel may be imported using this file type. Values may be separated by commas, spaces, or tabs.

A convex triangular mesh is generated, and each triangle in the mesh is considered planar when drawing contour levels. Areas outside the triangular mesh are not interpolated and not drawn. To delete extraneous triangles see the "How do I?" topic "How do I force DPlot to create a triangular mesh of my 3D points that is not convex?". You can generate a smoother plot after reading one of these file with the Generate Mesh command on the Options menu.

For surface plots, points with identical X,Y coordinates are removed, preserving the point with the maximum Z value. This differs from 3D scatter plots, for which all points are preserved.

This file format may optionally contain 3 title lines and X, Y, and Z axis labels preceding the data. If included, these lines should start and end with double-quotation marks. DPlot reads labels in the order 1st title line, 2nd title line, 3rd title line, X axis label, Y axis label, Z axis label. So if you want, for example, to include all axis labels but have only one title line, the 2nd and 3rd lines in the file should be pairs of double-quotation marks. Alternatively, if the X, Y, and Z axis labels are on the same line (such that there are 3 pairs of double quotation marks on this line), DPlot will interpret this line correctly regardless of whether any title lines precede it.

For a table of Z values

If your data file consists of Z values only, with each line of the file containing Z values at a constant Y and each column corresponding to a different X, select the Open command on the File menu. Select file type L on the Select File Type dialog and the Z Table plugin module:

The Z Table plugin is an optional component; if you do not see this entry under Plugins you will need to reinstall DPlot to use it. This format is an ASCII text file containing Z values only. Each line of Z values in the file corresponds to a constant Y value. Likewise each column corresponds to a constant X. Comma-separated values (CSV) files produced by Microsoft Excel may be imported using this file type. Values may be separated by commas, spaces, or tabs.

After clicking OK and selecting a file you will be presented with a dialog box prompting you for the X and Y extents:

Rows and columns are assumed to be evenly-spaced between the specified extents.

Regardless of the file format, the surface will generally be presented initially as a 2D view with contour lines. To switch to 3D or for other rendering options, see the Contour Options command on the Options menu.

 

 


Page url: https://www.dplot.com/help/index.htm?helpid_gs_xyzsurf_file.htm