When undertaking Select Link Analysis in Cube Voyager Highway program, it is possible to specify the VOL[#] sub-keyword to reserve the volume set # to store the Select Link volume.
Care should be taken when setting these additional VOLs and Turns at the same time. Refer to our Reference Guide under Highway Program > Control Statements > TURNS. The manual explicitly reports that:
- By default, the single volume is computed by adding all the individual turn volume sets together (T = TURN + TURN  + TURN [..] ...)
- Usually, the T= expression should be parallel to the V= expression that is specified on a FUNCTION statement
- If additional volume sets are required for SELECTLINK analysis, only the turn volume sets corresponding to the original volume indices should be summed. This avoids double counting in the TURNS request
- The value of T for each movement will be computed in the Adjust phase, and then combined with other iteration values to form the “combined” volume
Also, within the SELECTLINK keyword explanation, the user guide is reporting that with SELECTLINK and the TURNS control statement in the same HIGHWAY program, care must be taken.
The catalog below:
SLA_with_Turns.zip (1.6 MB)
...shows this behavior with 5 simple tests assigning two matrices, therefore with V=VOL+VOL and using a VOL when undertaking SLA. This should clarify how to properly set these statements within your script.
Highway programs #1, #2 and #3 provide the same results and convergence measures (#1=#2=#3):
- HW program #1 does not include any SLA and does not include the TURNS statement
- HW program #2 includes SLA + VOL and include the TURNS statement T=TURN+TURN
- HW program #3 includes SLA (but without VOL) and does not include the TURNS statement
Highway programs #4 and #5 provide different results and convergence measures than tests #1, #2, #3, but the results and convergence measure are the same between #4 and #5 (#4=#5):
- HW program #4 includes SLA + VOL and does not include the TURNS statement
- HW program #5 includes SLA + VOL and include the TURNS statement T=TURN+TURN+TURN