The following patch makes equality in DFLOAT conform to the IEEE 754 standard concerning equality:
"According to the IEEE 754 standard, negative zero and positive zero should compare as equal with the usual (numerical) comparison operators, like the == operators of C and Java. " https://github.com/billpage/fricas/commit/cfd3150613557acfb5a7986c6561b3ee84f09727 https://github.com/billpage/fricas/commit/cfd3150613557acfb5a7986c6561b3ee84f09727.patch -- >From cfd3150613557acfb5a7986c6561b3ee84f09727 Mon Sep 17 00:00:00 2001 From: Bill Page <bill.p...@newsynthesis.org> Date: Sun, 16 Sep 2018 14:57:29 -0400 Subject: [PATCH] Use EQUALP for = --- src/lisp/primitives.lisp | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/lisp/primitives.lisp b/src/lisp/primitives.lisp index 1b3017e4..7aed05df 100644 --- a/src/lisp/primitives.lisp +++ b/src/lisp/primitives.lisp @@ -284,7 +284,8 @@ (progn (defmacro |less_DF| (x y) `(< (the double-float ,x) (the double-float ,y))) -(defmacro |eql_DF| (x y) `(EQL (the double-float ,x) +;; use EQUALP (or maybe just = ??) to be consistent with zero?_DF +(defmacro |eql_DF| (x y) `(EQUALP (the double-float ,x) (the double-float ,y))) (defmacro |expt_DF_I| (x y) `(EXPT (the double-float ,x) (the integer ,y))) -- This fixes the problem reported by Konrad. 'norm-out' does not find any regressions. On Sat, Sep 15, 2018 at 1:30 PM Bill Page <bill.p...@newsynthesis.org> wrote: > > Konrad Schrempf reports the following bug: > > (1) -> A := matrix([[0]])$Matrix(DFLOAT) > > (1) [0.0] > Type: Matrix(DoubleFloat) > (2) -> rowEchelon(A) > > (2) [0.0] > Type: Matrix(DoubleFloat) > (3) -> A := matrix([[-0$DFLOAT]]) > > (3) [-0.0] > Type: Matrix(DoubleFloat) > > (4) -> rowEchelon(A) > > >> Error detected within library code: > not invertible > > (5) -> zero?(-0$DFLOAT) > > (5) true > Type: Boolean > (6) -> zero?(0$DFLOAT) > > (6) true > Type: Boolean > (7) -> (-0$DFLOAT ~= 0$DFLOAT)@Boolean > > (7) true -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
