[MATH-1414] Method reciprocal() in Complex for complex numbers with parts very close to 0.0

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Won't Do
• Fix Version/s: 4.0

Docs Text

 

• Assignee: Unassigned
• Reporter: Gunel Jahangirova
• Created: 19/Apr/17 09:44
• Updated: 01/May/17 23:06
• Resolved: 01/May/17 23:06

Description

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

Complex complex0 = new Complex((-2.44242319E-315));
Complex complex1 = complex0.reciprocal();

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

if (real == 0.0 && imaginary == 0.0) {
      return INF;
}

should be replaced by the equality check with some tolerance (0.01 in this case):

if (equals(this, ZERO, 0.01)) {
     return INF;
}

Issue Links

• relates to: NUMBERS-22 Method reciprocal() in Complex for complex numbers with parts very close to 0.0