circular spline

[doby]

I need to create a spline for a repeating pattern 0 to 2PI.  The requirements are:

1) needs to be continuous and for the first derivative.  

2) needs to start and end at the same point and have a continuous derivative.  

3) one segment needs to be perfectly linear.  

Any help would be appreciated.  

Thanks

[RichardJ]

As implied by the filename, none of this was written by me.

[Fred_Kohlhepp]

I miss Mr. Gutman!