Skip to content

Use flhypot in matrix-2norm to fix the failing test #124

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
pavpanchekha merged 2 commits into from
Oct 8, 2026
Merged

Use flhypot in matrix-2norm to fix the failing test #124

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9d1f81f
Use flhypot in matrix-2norm to fix the failing test
pavpanchekha Oct 4, 2026
6324c72
Use flhypot directly in matrix-2norm
pavpanchekha Oct 8, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 5 additions & 5 deletions math-lib/math/private/matrix/matrix-basic.rkt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -229,11 +229,11 @@
(define (matrix-2norm M)
(parameterize ([array-strictness #f])
(let ([M (array-strict (inline-array-map nonstupid-magnitude M))])
;; Compute this divided by the maximum to avoid underflow and overflow
(define mx (array-all-max M))
(cond [(and (rational? mx) (positive? mx))
(* mx (sqrt (array-all-sum (inline-array-map (λ (x) (sqr (/ x mx))) M))))]
[else mx]))))
(cond
[(array-all-and (inline-array-map exact? M))
(sqrt (array-all-sum (inline-array-map sqr M)))]
[else
(array-all-fold (inline-array-map fl M) flhypot 0.0)]))))

(: matrix-inf-norm (case-> ((Matrix Flonum) -> Nonnegative-Flonum)
((Matrix Real) -> Nonnegative-Real)
Expand Down
7 changes: 7 additions & 0 deletions math-test/math/tests/matrix-tests.rkt
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -641,6 +641,13 @@
(check-equal? (matrix-norm (matrix [[1e200 1e199]]))
(flhypot 1e200 1e199))

;; Mixed exact and inexact entries use the flonum hypot path.
(check-equal? (matrix-norm (matrix [[1 2.0]]))
(flhypot 1.0 2.0))

;; A NaN entry should propagate through the flonum hypot path.
(check-true (nan? (matrix-norm (matrix [[+nan.0]]))))

;; Taxicab (Manhattan) norm
(check-equal? (matrix-norm (matrix [[1 2 3] [4 5 6]]) 1)
(+ 1 2 3 4 5 6))
Expand Down
Loading