The equals() implementation for Real checks for identical significand, error and exponent. Instead, use approximates(), which "takes into account possible errors (e.g. numeric errors)." Addendum: See also these articles as regards floating point comparison: What Every Computer Scientist Should Know About Floating-Point Arithmetic What Every Programmer Should Know About Floating-Point...

java,algorithm,geometry,jscience,trilateration

A negative value for z1 would indicate no real solution, e.g. the intersection of the first and second sphere falls entirely inside or outside of the the third sphere. If your test values do not include at least one set for which a real solution exists, z1 will always be...

From the documentation: Sparse vectors can be created using an index-to-element mapping or by adding single elements sparse vectors together. This corresponds to the first two static valueOf methods. Single Element valueOf(int dimension, F zero, int i, F element) Returns a sparse vector having a single element at the specified...