# Commits

committed f43115d

Add date modified, reindent/recomment some sections

• Participants
• Parent commits 6bef65a

# File reals.lisp

` ;;;; 1989-06-11, 1989-06-12, 1989-06-13, 1989-06-14, 1989-06-17, 1989-06-30`
` `
` ;;;; Modified by Robert Smith`
`-;;;; 2011-12-07`
`+;;;; 2011-12-07, 2012-05-26`
` `
` ;;;;   I N T E R N A L   S T R U C T U R E S   A N D   I N T E R F A C E`
` ;;;;   -----------------------------------------------------------------`
`   (declare (type creal x))`
`   (let ((a (get-approx x 3)))`
`     (cond ((<= -3 a 3) (atan-r1 x))`
`-          ((< a -3) (minus-r (atan-r0 (minus-r x)))) ; atan(x) = -atan(-x)`
`+`
`+          ;; atan(x) = -atan(-x)`
`+          ((< a -3) (minus-r (atan-r0 (minus-r x))))`
`+          `
`+          ;; atan(x) = pi/4 + atan((x-1)/(x+1))`
`           ((< 3 a 17) (+r +pi/4-r+ (atan-r1 (transf x))))`
`-                    ; atan(x) = pi/4 + atan((x-1)/(x+1))`
`-          (t (-r +pi/2-r+ (atan-r1 (invert-r x))))))) ; atan(x) = pi/2 - atan(1/x)`
`+`
`+          ;; atan(x) = pi/2 - atan(1/x)`
`+          (t (-r +pi/2-r+ (atan-r1 (invert-r x))))))) `
` `
` ;;; (atan-r x [y]) computes the arctangent of the creals x (and y if given)`
` `