;Roof pitch utility by Mike Grisez

;*********************************** RTD *********************************
;Converts radians to degrees
(defun rtd (r)
  (* 180 (/ r pi))
)

;******************************** DTR ************************************
;Converts degrees to radians
(defun dtr (a)
   (* pi (/ a 180.0))
)
;****************************** TAN ****************************************
;Tangent function
(defun tan (an)
  (/ (sin an) (cos an))
)

;*******************************  PITCH ***********************************
;Gives roof angle in degrees from roof pitch
(defun c:pitch (/ rp ang)
  (setq rp (getdist " What is the Roof Pitch? (? in 12): ")) (terpri)
  (setq ang (rtd (atan (/ rp 12.0))))
  (prompt "The Roof Slope is: ") (princ ang) (prompt " degrees")
  (princ)
)


;**************************** COMMAND GETPITCH ******************************
(defun C:getpitch ()
  (setq ang (getdist "The Angle in Decimal Degrees? ")) (terpri)
  (setq dd  (* (tan (dtr ang)) 12.0))
  (prompt "The Roof Pitch is: ") (princ (rtos dd 3 2 )) (prompt " in 12") (terpri)
  (princ)
)
(prompt "Command Pitch = ?/12 to Degrees, Command Getpitch = Degrees to ?/12")
  (princ)