9.3 Yield Menu
9.3.1 Calculate Yields
 
The Calculate Yields function is the link between the polygon data that has been entered and two external yield table programs, VDYP Batch and BTIPSY. This function is used to derive yield tables for each polygon, for use in the calculations in WOODLOT.
To calculate yields, ensure your polygon data is complete, and click on Calculate Yields. Another screen Calculate Yield Tables is activated as shown below. Should you have any errors or incomplete information in your data, this will be displayed in the two list boxes:
- Pre-calculation errors: this list box shows errors that should be corrected before calculating the yields. Uncorrected errors will result in incorrect yield tables for this polygon.
- Pre-calculation warnings: this list box shows warnings to prompt the user that some polygon data exceeds normal specifications. Running a calculation with these warnings will not result in errors in the yield tables, but will affect the yield information used in subsequent calculations. Items that may be displayed relate to management decisions the user must make, such as whether or not to use a volume adjustment factor (VAF) to scale down VDYP yields to reflect actual cruise volumes.
Three checkboxes are also provided. They will also indicate the number of polygons that must have yields updated. Select on these to either:
- update just the VDYP yield tables
- update just the TIPSY yields tables
- update both VDYP and TIPSY yield tables
This feature was provided as a calculations time saver. It is also a way of indicating/knowing whether any new information you have entered will require yield tables to be re-run.
To produce yield tables for each polygon, click on the Calculate Yield button. The following actions will occur:
- for those polygons selected for VDYP yields (i.e. natural stands, or stands with deciduous), this will send a command to VDYP with your input data to generate yield table information for all polygons.
- a black DOS screen will appear while the VDYP calculations occur. The cursor will be displayed in this screen, blinking. It will take several seconds for this calculation, depending on the speed of your computer. One screen dot is displayed for each 10 VDYP polygons.
- Once compiled, the VDYP yield information will be imported into WOODLOT and a windows screen will appear briefly to show the import function happening.
- The calculation will immediately restart for those polygons selected for TIPSY yields (i.e. managed stands without deciduous), which will send a command to TIPSY with your input data to generate yield table information for all polygons. A black DOS screen will again appear briefly while calculations occur. Because of the speed of calculations in TIPSY, it will only take a split second to compile yield information, depending on the speed of your computer.
- Just as for VDYP, once compiled, the TIPSY yield information will be imported into WOODLOT and a windows screen will appear briefly to show the import function happenin
- Should an error occur, VDYP and TIPSY will generate an error file. A message will be displayed, as shown below, asking if you would like to view the error. The error file generated will be loaded into NOTEPAD. If a screen called 'FIND PROGRAMS' appears please see section "16.4 Directories/Programs Locations" page 16-95 for more information.
Please see section section "2.10 Closing the DOS Screen Window Automatically" page 2-9 for more information on how to close out DOS screens that may remain after you calculate yields.
9.3.2 View Existing Yield
The View Existing Yield function will open a window that displays all the output data generated by either VDYP or TIPSY for the first rotation. See section "10.0 Yield Table" page 10-58 for more information.
9.3.3 View Future Yield
View Future Yield function will open a window that displays all the output data generated by either VDYP or TIPSY for all subsequent rotations. See section "10.0 Yield Table" page 10-58 for more information.
|
![[enfor consultants ltd]](/clipart/n4logo1.gif)
