To draw a surface plot using a data file,
- load the data file. The file should have atleast three columns (say a, b, c)
in row-by-row format as shown below
a1, b1, c11
a1, b2, c12
a1, b3, c13
...
a2, b1, c21
a2, b2, c22
a2, b3, c23
...
- In the surface plot, the base plane is XZ plane and height axis is the Y-Axis. (For convenience the combo (drop down) boxes are ordered X, Z, Y).
Select the columns in X and Z axis comboboxes. (In the example given in point#1 (a,b,c) map to (x, z, y))
- Then select the Y-Axis combo box.
- To determine the Y value for a particular (X,Z) we
interpolate the Y values of near by (X,Z) points from the data file.
User can choose between BiLinear or BiCubic Spline interpolation from the Interpolation combo box.
- Clicking "Plot" button draws the surface plot.
- You can use the MeshLine multiplier combo boxes to change the number of mesh lines to be drawn. Value can vary from 0.1 to 1 insteps of 0.1
- You can use the Smoothness combo boxes to smoothen the surface. Value can vary from 1 to 2 in steps of 0.1. Higher the value the surface is more smooth and the time taken to render the surface is more
Setting "Smoothness" changes the number of block counts on X axis, while "Mesh Line multiplier" represents number of blocks on Y axis. The smoothness or mesh line multiplier values can be set in the range between 0-2.
Enter line of sight in Plot:
You can set the line of sight of all the three axis by clicking of "Enter Line of Sight" sub menu of "View" menu. Clicking on this sub menu prompts up a dialog which shows three angles Theta, Phi and Psi. Theta, Phi and Psi are angles from the line of sight to the X, Y and Z axis respectively. Changing their values and clicking on "Apply" applies changes to the cubic grid of plot.
The Enter Line of Sight dialog is shown in Figure 1
Figure 1. Enter Line of Sight