## radian 弧度
## degree 角度

## 弧度 转 角度
radian2degree <- function(radian) {(radian * 180) / (pi)}

## 角度 转 弧度
degree2radian <- function(degree) {(degree * pi) / (180)}

# 调用示例:
radian2degree(pi) # pi 转为 180
radian2degree(2*pi) # 2pi 转为360
degree2radian(180) # 180 转为 pi

REF

https://cloud.tencent.com/developer/ask/50738