TI-83 Plus Statistics 362
SinReg—a sin(bx+c)+d
SinReg (sinusoidal regression) fits the model equation y=a sin(bx+c)+d to
the data using an iterative least-squares fit. It displays values for a, b, c,
and d. At least four data points are required. At least two data points per
cycle are required in order to avoid aliased frequency estimates.
SinReg [iterations,Xlistname,Ylistname,period,regequ]
iterations is the maximum number of times the algorithm will iterate to find
a solution. The value for iterations can be an integer ‚ 1 and 16; if not
specified, the default is 3. The algorithm may find a solution before
iterations is reached. Typically, larger values for iterations result in longer
execution times and better accuracy for SinReg, and vice versa.
A period guess is optional. If you do not specify period, the difference
between time values in Xlistname must be equal and the time values must
be ordered in ascending sequential order. If you specify period, the
algorithm may find a solution more quickly, or it may find a solution when
it would not have found one if you had omitted a value for period. If you
specify period, the differences between time values in Xlistname can be
unequal.
Note: The output of SinReg is always in radians, regardless of the Radian/Degree
mode setting.