# Model functions

## cos() function

cos(`v,r`)
forms cosine from `v` with period `r`.
Omit `r`
if `v` is radians.
If `v` is degrees,
`r` is 360.
## sin() function

sin(`v,r`)
forms sine from `v` with period `r`.
Omit `r`
if `v` is radians.
If `v` is degrees,
`r` is 360.
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