Indicator_Geology &endash; Material Probabilities

Now, let’s make a small addition to our network (application). We’ll add a second Legend module because we’re going to need a scale to show us what probabilities our colors represent. Disconnect the first Legend and add Legend#1 as shown below:

$image\site_t_indicator_geology_net-prob2.jpg$

Turn on all materials in Explode_and_Scale.

Now open the select_data module’s window and choose Probability:

$image\wb-12-014.jpg$

Open Legend#1’s two windows and match the settings below:

$image\wb-12-012.jpg$

$image\wb-12-013.jpg$

Click on Accept All Current Values and the second legend will be created.

Your Viewer will show the probability that was computed for each cell’s material assignment. Note that we are seeing probabilities on the near surface that range from near 1.0 down to about 0.25. Even though the probability may be low, the selected material had the highest probabilities of all the available materials.

$image\wb-12-015.jpg$

Note that the coloring is rather blocky. That is because we are dealing with cell data versus nodal data. Cells are now colored a single color based on the value assigned to the entire cell. With nodal data, the data was assigned to the corners of cells and the colors were interpolated across each face of the cell. Each hexahedron cell could have markedly different face colors with nodal data, but here the colors are constant for each cell (actually the color is constant, but the shading can still affect the brightness of a cell’s face depending on the angle to the light source).

Go back to Explode_and_Scale and once again let’s turn on only Gravel.

$image\wb-12-011.jpg$

The probability of Gravel within the Gravel material is now displayed in the Viewer.

$image\site_t_4-prob.jpg$

Note: If you change select_data to Gravel Prob., the picture doesn’t change! This is important and fundamental to what we’re doing. The Indicated Material is that material which had the highest computed probability for each individual cell. The Probability cell data component is the highest computed probability for every cell regardless of material, however the material that gave the highest probability is the one we select!

Therefore, the Probability within the Gravel will always be the same as the Gravel Prob. within the gravel.

However, in the gravel zone, the probabilities that any of these cells could be any other material will be lower. Let’s look at the Gravel Prob(ability) from a different view. With a -20 degree elevation it looks like:

$image\site_t_4-prob-20.jpg$

Now if we change to color by Clay Prob(ability) our picture changes to:

$image\wb-12-016.jpg$

Note that over most of the gravel, the clay probability is much lower, but for the near region at the bottom (where we bound clay!), the probability is nearly identical! At the boundaries between materials, the probabilities will be nearly equal and this tells us that the material assignment here is rather ambiguous.

We’ll look at another example. If we choose Explode_and_Scale and select Clay and in select_data’s window choose Clay Prob(ability):

$image\site_t_0-prob.jpg$

Now if you change select_data to Gravel Prob most of the picture changes, but the near top surface is nearly the same (since it borders gravel).

$image\wb-12-017.jpg$