Mercurial > hg > octave-nkf
changeset 19484:238522618904
nthroot.m: Fix division by zero warning when input x is 0 (bug #43492).
* nthroot.m: Check whether input is a scalar 0, and don't apply integer
correction to calculated root as this leads to a division by zero.
Add BIST test for bug.
| author | Rik <rik@octave.org> |
|---|---|
| date | Wed, 29 Oct 2014 08:21:24 -0700 |
| parents | 64f034147e9a |
| children | b80b396e7d54 |
| files | scripts/specfun/nthroot.m |
| diffstat | 1 files changed, 13 insertions(+), 4 deletions(-) [+] |
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--- a/scripts/specfun/nthroot.m +++ b/scripts/specfun/nthroot.m @@ -74,11 +74,14 @@ endif if (integer_n && n > 0 && isfinite (n)) - ## FIXME: What is this correction for? - y = ((n-1)*y + x ./ (y.^(n-1))) / n; - y = merge (isfinite (y), y, x); + if (isscalar (y) && y == 0) + ## Don't apply correction which leads to division by zero (bug #43492) + else + ## FIXME: What is this correction for? + y = ((n-1)*y + x ./ (y.^(n-1))) / n; + y = merge (isfinite (y), y, x); + endif endif - endif endfunction @@ -90,6 +93,12 @@ %!assert (nthroot (-Inf, 7), -Inf) %!assert (nthroot (-Inf, -7), 0) +## Bug #43492. This should not generate a division by zero warning +%!test +%! warnmsg = lastwarn (); +%! assert (nthroot (0, 2), 0); +%! assert (lastwarn (), warnmsg); + %% Test input validation %!error nthroot () %!error nthroot (1)