|
|
|
|
|
Recalculating Winds Distribution (FSPro)
After setting all of the parameters on the FSPro Winds screen, clicking Generate Wind Matrix, and looking at the matrix or viewing the Wind Rose, a Fire Behavior Specialist may decide to redistribute values in the matrix using the Recalculate Winds Distribution button located at the bottom of the matrix. There are two common reasons for using Recalculate Winds Distribution is in conjunction with the Add Row and Delete Row buttons.
When using the Add Row button to add a row to the bottom of the matrix, all wind directions will have values of zero. To fill these using the existing parameters, click the Recalculate Winds Distribution button; using Generate Winds Matrix will delete the added row since this button re-generates the wind data using the existing parameters.
When Delete Row is used, the distributions in remaining rows do not change, but the Total Weight of the matrix will continue to decrease as rows are deleted. This means that some wind data are not represented in the matrix. In order to redistribute all of the wind data among existing rows, click Recalculate Winds Distribution. If rows are deleted and Generate Wind Matrix is clicked, the deleted rows will be added back to the matrix. The Delete Row button only deletes from the bottom of the matrix, not the top. Recalculating the Winds Distribution after increasing the Calm Threshold is one way to set low windspeeds to zero, though this is also accomplished by increasing the Calm Threshold and clicking Generate Wind Matrix.
It is possible to use the Recalculate Winds Distribution in other ways. When wind parameters are modified, clicking Recalculate Winds Distribution redistributes the new wind data among the existing wind speed rows and, unlike the Generate Wind Matrix button, rows will not be added or subtracted from the matrix. For example, if an analyst decides to use Gusts instead of Ten Min Avg average winds, it is appropriate to click Generate Wind Matrix to change both the distribution and (in most cases) the highest wind speed row. If parameters are modified (e.g. change Wind Type from Ten Min Avg to Gusts) and Recalculate Winds Distribution is clicked, the new wind data are redistributed within the existing matrix without creating new rows. Use caution when manipulating the wind matrix this way as it may be difficult to defend these types of edits because it can make the values in the wind matrix difficult to interpret and less transparent to another viewer.
-----------
Last updated on 12/7/2017 12:52:32 PM.
In This Section |
See Also |
Reference |