Commit bacaecf2 authored by Daniel Kochmański's avatar Daniel Kochmański

atan: add atan2 tests for 0 arguments

parent 8cdbbad8
......@@ -126,6 +126,55 @@
;;; FIXME
;;; More accuracy tests here
;;; ieee-fp tests
(deftest atan.ieee.1 :description "Verify if atan handles 0.0 correctly"
;; (atan +-0 +(anything-but-nan)) -> +-0
;; (atan +-0 -(anything-but-nan)) -> +-pi
(flet ((pip (a b)
;; we are not testing accuracy, so this simplified
;; precdicate would be sufficient for our needs. We are
;; also not interested in sign of the result, because we
;; don't know whenever zero is signed or not.
(<= (abs (- (abs a) (abs b))) 0.01)))
(every #'identity
(append
(map 'list (lambda (n)
;; notice, that we don't test a case, where
;; both arguments are 0.0, because if
;; implementation doesn't support signed 0
;; result is undefined.
(and (zerop (atan -0.0 n))
(zerop (atan +0.0 n))
(pip pi (atan +0.0 (- n)))
(pip pi (atan -0.0 (- n)))))
(remove-if-not #'plusp *floats*))
;; (atan +-(anything-but-0/nan) 0) -> +-pi/2
(map 'list (lambda (n)
(and (pip (* +1/2 pi) (atan n +0.0))
(pip (* -1/2 pi) (atan n -0.0))))
(remove-if #'zerop *floats*)))))
T)
;;; We could have tested also for infinities and signed 0, but there
;;; is no portable ieee-fp, we could put it in ansi-beyond test suite
;;; though:
;;;
;;; (atan +0.0 -anything-but-0/nan/inf) -> +pi
;;; (atan -0.0 -anything-but-0/nan/inf) -> -pi
;;; (atan +0.0 +0.0) -> +0.0
;;; (atan -0.0 +0.0) -> -0.0
;;; (atan +0.0 -0.0) -> +pi
;;; (atan -0.0 -0.0) -> -pi
;;; (atan (anything) nan) -> nan
;;; (atan nan (anything)) -> nan
;;; (atan +-inf +inf) -> +-pi/4
;;; (atan +-inf -inf) -> +-3pi/4
;;; (atan +-(anything-but-inf/nan), +inf) -> +-0
;;; (atan +-(anything-but-inf/nan), -inf) -> +-pi
;;; (atan +-inf (anything-but-0/nan/inf)) -> +-pi/2
;;;
;;; (deftest atan.ieee.2 t t)
;;; Error tests
(deftest atan.error.1
......@@ -147,7 +196,3 @@
(deftest atan.error.5
(check-type-error #'(lambda (x) (atan 1 x)) #'realp)
nil)
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