FORCOS
The FORCOS function evaluates a Fourier Cosine series at a user-specified value x. The x0, a0, a1,...,a30 are parameters used to define the constants for the Fourier Cosine series.
Format
FORCOS (x, x0, w, a0, a1,...,a30)
Arguments
x | A real variable that specifies the independent variable. For example, if the independent variable in the function is time, x is the system variable TIME. |
x0 | A real variable that specifies a shift in the Fourier Cosine series. |
w | A real variable that specifies the fundamental frequency of the series. Adams Solver (FORTRAN) assumes w is in radians per unit of the independent variable unless you use a D after the value. |
a0 | A real variable that defines the constant bias term for the function. |
a1,...,a30 | The real variables that define as many as thirty-one coefficients for the Fourier Cosine series. |
Extended Definition
The Fourier Cosine series is defined:
where the function 
are defined as:
are defined as:
The index j has a range from 1 to n, where n is the number of terms in the series.
Examples
MOTION/1, JOINT=21, TRANSLATION,
, FUNCTION=FORCOS(TIME, 0, 360D, 1, 2, 3, 4)
, FUNCTION=FORCOS(TIME, 0, 360D, 1, 2, 3, 4)
This MOTION statement defines a harmonic motion as a function of time. The motion has no shift, has a fundamental frequency of 1 cycle (360D) per time unit, has a constant value of 1.0. The function defined is:
FORCOS = 1+2*COS(1*360D*TIME)
+3*COS(2*360D*TIME)
+4*COS(3*360D*TIME)
+3*COS(2*360D*TIME)
+4*COS(3*360D*TIME)
The curve is shown next.
Curve of a Harmonic Motion Defined by FORCOS
See other General available.