Package: emacs;
Reported by: Christopher Howard <christopher.howard <at> qlfiles.net>
Date: Mon, 22 Apr 2019 05:38:01 UTC
Severity: normal
Tags: confirmed, fixed, patch
Fixed in version 26.4
Done: Mattias Engdegård <mattiase <at> acm.org>
Bug is archived. No further changes may be made.
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From: Mattias Engdegård <mattiase <at> acm.org> To: Christopher Howard <christopher.howard <at> qlfiles.net> Cc: 35374 <at> debbugs.gnu.org Subject: bug#35374: Calc; Div by 0 in solving system Date: Tue, 23 Apr 2019 16:34:58 +0200
21 apr. 2019 kl. 17.37 skrev Christopher Howard <christopher.howard <at> qlfiles.net>: > I enabled Debug on Error but could not find the backtrace Reproduced in 26.1. Backtrace below. I quickly got lost in calcalg2.el, but it looks like the equation 2(z - 1.0) - (5 + 3(z - 1.0) - z) / 2 + 3z + 3 = 0, isn't solved properly by math-try-solve-for: math-decompose-poly returns the correct decomposition of the LHS, (4) * z, but then the code decides to find a root of the polynomial (4) which of course doesn't exist and nothing good comes out of it. I'm not sure why the floating-point numbers (float 1 0) are there in the first place. Maybe someone more knowledgeable about Calc can help further. * math-reject-arg((float 1 0) "*Division by zero") math-div-by-zero((float 1 0) 0) math-div((float 1 0) 0) math-float((frac 1 0)) math-mul((frac 1 0) (float 138629436111989 -14)) math-mul-objects-fancy((frac 1 0) (cplx (float 138629436111989 -14) (float 314159265358979 -14))) math-mul((frac 1 0) (cplx (float 138629436111989 -14) (float 314159265358979 -14))) math-pow-fancy(-4 (frac 1 0)) math-pow(-4 (frac 1 0)) math-poly-laguerre-root((4) 0 t) math-poly-any-root((4) 0 t) math-try-solve-for((+ (+ (- (* 2 (- (var z var-z) (float 1 0))) (/ (- (+ 5 (* 3 (- (var z var-z) (float 1 0)))) (var z var-z)) 2)) (* 3 (var z var-z))) 3) 0 nil nil) math-try-solve-for((calcFunc-eq (+ (- (* 2 (- (var z var-z) (float 1 0))) (/ (- (+ 5 (* 3 (- (var z var-z) (float 1 0)))) (var z var-z)) 2)) (* 3 (var z var-z))) -3) 0 nil) math-solve-for((calcFunc-eq (+ (- (* 2 (- (var z var-z) (float 1 0))) (/ (- (+ 5 (* 3 (- (var z var-z) (float 1 0)))) (var z var-z)) 2)) (* 3 (var z var-z))) -3) 0 (var z var-z) nil) math-solve-system-rec((((calcFunc-eq (+ (- (* 2 (- (var z var-z) (float 1 0))) (/ (- (+ 5 (* 3 (- (var z var-z) (float 1 0)))) (var z var-z)) 2)) (* 3 (var z var-z))) -3))) ((var z var-z)) (((var y var-y) (- (var z var-z) (float 1 0))) ((var x var-x) (/ (- (+ 5 (* 3 (- (var z var-z) (float 1 0)))) (var z var-z)) 2)))) math-solve-system-rec((((calcFunc-eq (- (+ (/ (- (+ 5 (* 3 (var y var-y))) (var z var-z)) 2) (var y var-y)) (* 2 (var z var-z))) 0)) ((calcFunc-eq (+ (- (* 2 (var y var-y)) (/ (- (+ 5 (* 3 (var y var-y))) (var z var-z)) 2)) (* 3 (var z var-z))) -3))) ((var y var-y) (var z var-z)) (((var x var-x) (/ (- (+ 5 (* 3 (var y var-y))) (var z var-z)) 2)))) math-solve-system-rec((((calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5)) ((calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0)) ((calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3))) ((var x var-x) (var y var-y) (var z var-z)) nil) math-solve-system((vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)) nil) calcFunc-solve((vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z))) apply(calcFunc-solve ((vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) math-normalize((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) math-simplify((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) calc-normalize-fancy((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) calc-normalize((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) math-evaluate-expr((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z)))) mapcar(math-evaluate-expr ((calcFunc-solve (vec (calcFunc-eq (+ (- (* 2 (var x var-x)) (* 3 (var y var-y))) (var z var-z)) 5) (calcFunc-eq (- (+ (var x var-x) (var y var-y)) (* 2 (var z var-z))) 0) (calcFunc-eq (+ (- (* 2 (var y var-y)) (var x var-x)) (* 3 (var z var-z))) -3)) (vec (var x var-x) (var y var-y) (var z var-z))))) #f(compiled-function () #<bytecode 0x4a71afd9>)() calc-do(#f(compiled-function () #<bytecode 0x4a71afd9>) 126) calc-evaluate(1) funcall-interactively(calc-evaluate 1) call-interactively(calc-evaluate nil nil) command-execute(calc-evaluate)
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