Calculate trisolation statistics
You use the trisolation statistics function to generate statistics for the triangles in one or more trisolations. Trisolation statistics can be calculated for a 2D DTM or a 3D solid. You can use the statistics to identify problems in a trisolation and to see detailed feedback on the success of solids conditioning.
To run this function: Choose Solids > Validation > Calculate Trisolation Statistics, or...
When you open the Trisolation Statistics form, it is filled with values for all objects and trisolations of the loaded .dtm file currently displayed in Graphics. You can use the object and trisolation range fields to restrict the trisolations that the statistics are run for. You need to Refresh to see the statistics for the restricted range.
The statistics are calculated by measuring each triangle in the selected trisolations and then calculating the Min (minimum), Max (maximum), Standard Deviation and Mean for different groups. The table on the bottom of the form shows the summary for the entire selected range of trisolations. Additional information can be examined in a statistics report.
Fields on the Trisolation Statistics form
| Field | Description |
|---|---|
| Layer name | The name of the active layer. |
| Object Range | The objects in the layer for which you want to generate statistics. To process all objects, leave this field blank. |
| Trisolation Range | The trisolations in the object for which you want to generate statistics. To process all trisolations, leave this field blank. |
| Report file | The name, file extension, and file path for the statistics report. The file extension you choose determines the format of the report. If you do not want to generate a report, leave this field blank. |
| Number of Objects |
The total number of objects in the data range selected. |
| Number of Trisolations |
The total number of trisolations in the data range selected. |
| Number of triangles | The total number of triangles in the data range selected. |
| Number of vertices | The total number of vertices in the data range selected. |
| Total surface area | The total surface area calculated of the data range selected. |
| Statistics table |
A summary of statistics for the data selected. This summary includes the:
|
Output
The Areas, Small Angles, Large Angles and H/W Ratios (height-to-width) are generated as histograms in the tabs named on the Trisolation Statistics form. These show the numbers of triangles that fall into each numerical range. The range for the Areas is calculated from the actual ranges of triangle areas across the selected trisolations. The ranges for the other three charts are fixed. Small angles are below 60 degrees. Large angles are above 60 degrees. The ratio of height-to-width varies from 0.0 to 1.0.
Note: The width of a triangle is defined as the longest edge regardless of orientation.
You can click Report to generate a more detailed report based on the statistics summarised on the Statistics tab of the Trisolation Statistics form. The default format for the report is a CSV file, which is suitable for importing into a spreadsheet. You can also create the report as a PDF, or in other formats.
The first line of the report is the summary, as seen on the Trisolation Statistics form. Below the summary there is a breakdown of the statistics by object and by trisolation. In addition, the validity status is shown. You can use the report to see if you have only one problem trisolation, by looking for a trisolation that has statistics that stand out. For example, a trisolation with extreme values such as a Min Area or a Min Small Angle that is near zero.