RockWorks | ModOps | Grid | Statistics | Standardize
This program is used to re-compute the grid node values such that they represent the standard deviations from the mean. When examining the new model, node values between zero and 1 can be considered background. Values between 1 and 2 can be considered slightly anomalous. Values between 2 and 3 are moderately anomalous. Values between 3 and 4 are strongly anomalous. Values above 4 are extremely anomalous. When comparing different types of geochemistry (e.g. PCB's vs TDS) , it is often useful to standardize the models first and then divide them by each other.
This program requires that a real number RockWorks grid model (.RwGrd file) already exists.
Menu Options
Step-by-Step Summary
- Grid Names
- Input Grid: Click to browse for the name of the existing grid model (.RwGrd file) to be analyzed.
- Output Grid: Click here to type in the name to assign to the new grid file that the program will create, which results from the node-standardizing operation
- Options
- Compute Absolute Values: Insert a check here to store the computed standard deviations as their absolute values (e.g. positive). This can be helpful if you wish to view anomalies in general. This should be left un-checked if it's important to know whether the values are above or below the mean.
- Set Background Values to Zero: Insert a check here to filter out non-anomalous values.
- Background Threshold: Enter the standard deviation to be considered background and set to zero. For example, if your analysis would not consider standard deviations less than "1.0", then you can set this as the threshold. In this example, this filter would set standardized node values less than 1.0 to 0 in the output model.
- 2D Grid Map
Check this box to display the output grid as a 2D map at this time.
Click this tab to set up the 2D map layers (bitmap, symbols, labels, line contours, color-filled contours, labeled cells, map border, etc.).
- 3D Grid Diagram
Check this box to display the output grid as a 3D surface at this time.
Click this tab to set up the 3D map layers (surface colors, images, reference cage, etc.).
! You can request both a 2D and 3D representation of the grid model.
- Select the ModOps | Grid | Statistics | Standardize menu option.
- Enter the requested menu settings, described above.
- Click the Process button to continue.
The program will load the input grid file, compute the mean of the node values, and calculate the deviation of each grid node value relative to the mean, both above and below. In the output file, a "standardized" value of "2" for a node indicates that the node is 2 standard deviations above the mean. A node value of "-0.579" indicates that the node is 0.579 standard deviations below the mean. If you have requested, negative values will be stored as positives. In addition, if you have activated the background filter, the program will reset those values to zero. These standard deviation values will be stored in a new grid file on disk under the output file name you selected. The requested diagram(s) will be displayed in a RockPlot2D tab and/or RockPlot3D tab in the Options window.
- You can adjust any of the settings in the Options window and then click the Process button again to regenerate the diagram(s).
- If you have requested a map, it will be displayed in a RockPlot window. View / save / manipulate / print / export the map in the RockPlot2D or RockPlot3D window.
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