Mechanism Design and Mechanism Dynamics > Mechanism Design > Creating Mechanism Models > Modeling Entities > Servo Motors > User Defined Expression Definition > About the Functions Dialog Box
About the Functions Dialog Box
Access this dialog box from the Expression Definition dialog box, or when creating a user-defined measure in the Measure Definition dialog box. When you select one of the following functions, it appears as part of your definition in expression area.
The default variable x for the functions is time, t. You can select another variable, such as a measure, from the x = list at the top of the dialog box. You can also enter a constant value or an expression in the text box. You can select a function by double-clicking or by single-clicking and closing the dialog box. The function appears in the expression area with the selected variable or entered expression.
sin(x), cos(x), tan(x)
standard trigonometric functions
arc sine in range –90 to 90
arc cosine in range 0 to 180
base 10 logarithm
natural (base e) logarithm
absolute value. If x>0, the function returns x, otherwise it returns –x.
square root
round toward positive infinity
round toward negative infinity
The functions ceil(x) and floor(x) are not available for servo motors.