I tried to compile Hipparchus 2.0 (core) with Oracle JDK and got errors:
…hipparchus\analysis\function\Signum.java:44: error: cannot find symbol
symbol: method signum()
location: variable x of type DerivativeStructure
…hipparchus\analysis\function\Signum.java:50: error: cannot find symbol
location: variable x of type T
where T is type-variable:
T extends Derivative declared in method value
. . . . .
= = = = = = = = = = = = =
And yes, I can’t find signum() method in DerivativeStructure class, Derivative class and parent CalculusFieldElement class
Same compilation procedure with Hipparchus 1.8 is OK.