Arranging : Time, Tempo, Meter, Key, and Chords : Tempo Operations Window : S-Curve

S-Curve
The S-Curve page in the Tempo Operations window lets you create tempos that accelerate or decelerate by following a tempo curve with a definable breakpoint that determines mid-curve times and tempo values.
 
Advanced
When this option is selected, the selection range changes to the Main Time Scale format, and additional and modified options become available.
Calculate (Advanced Option)
Calculates either the selection end time, the start tempo, the end tempo or the curvature of the tempo change.
Selection Start and End
Displays the start and end points for the tempo change in the currently selected Main timebase. When an Edit selection is made, the Start and End fields will display the selection boundaries. Changing start or end values changes the selection range.
Start and End Time (Advanced Option)
Displays the absolute time for the selection end. When the Main Time Scale is set to Bars|Beats, the end time is displayed in the Sub Time Scale. When the Main Time Scale is set to any absolute timebase, the end time is calculated and displayed in Bars|Beats.
Tempo Start and End
Displays the tempo, in beats per minute (BPM), for the start and end points of the selected range. Changing the tempo causes the end time value to change.
Curvature
Specifies and displays a numerical and graphic representation of the tempo curve. Negative numbers indicate a more rapid tempo change at the start and end of the of the time range, with a low rate of change around the midpoint. Positive numbers indicate a low rate of change near the start and end of the selected range, with rapid tempo change around the midpoint. This value can be set with the Curvature slider.
Mid Point
Specifies the Main Time Scale location for the curve mid point. This value can be set with the Mid Point slider.
Mid Tempo
Specifies the tempo at the mid point. This value can be set with the Mid Tempo slider.
Resolution (Advanced Option)
Lets you select the BPM note value for your tempo setting.
*
Select “Follow Metronome Click” will set the tempo BPM note value to mirror the click value set in the meter markers.
Density (Advanced Option)
Lets you specify the density of the tempo change events written to the Tempo ruler.
Preserve Tempo after Selection
If selected, the previous tempo setting that was in effect at the selection end point is preserved after the selection. If unselected, the last tempo event created by the tempo operation continues to the end of the session, or until the next tempo event beyond the selected range.