[
https://issues.apache.org/jira/browse/MATH-1414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15974486#comment-15974486
]
Raymond DeCampo commented on MATH-1414:
---------------------------------------
0.01 is way too large of a tolerance.
I think a better approach would be to detect if one of the real or imaginary
parts is going to be infinite or NaN and then return the proper result. We
need to determine what the desired result in this situation is, e.g. in the
example above one could make a case for {{Complex.INF}};
{{Double.NEGATIVE_INFINTITY}} or {{Double.POSITIVE_INFINITY}} (where the last
two have imaginary part zero).
> Method reciprocal() in Complex for complex numbers with parts very close to
> 0.0
> -------------------------------------------------------------------------------
>
> Key: MATH-1414
> URL: https://issues.apache.org/jira/browse/MATH-1414
> Project: Commons Math
> Issue Type: Improvement
> Reporter: Gunel Jahangirova
> Priority: Minor
>
> In class Complex method reciprocal() returns INF only if the real and
> imaginary parts are exactly equal to 0.0. In the cases when real and
> imaginary parts are double numbers very close to 0.0, it does not hold. For
> example, if we run this code
> {code}
> Complex complex0 = new Complex((-2.44242319E-315));
> Complex complex1 = complex0.reciprocal();
> {code}
> the value of complex1.getReal() will be -Infinity and the value of
> complex1.getImaginary() will be NaN, instead of complex1 being equal to INF.
> I think the code in the method
> {code}
> if (real == 0.0 && imaginary == 0.0) {
> return INF;
> }
> {code}
> should be replaced by the equality check with some tolerance (0.01 in this
> case):
> {code}
> if (equals(this, ZERO, 0.01)) {
> return INF;
> }
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
