Quantity Object returns wrong values if max_val >> value (or min_val << value)

[MaxNaeg]

Describe the bug

If the min or max value of a Quantity object are set to a very different order of magnitude compared to the actual value, the normalized value that is stored is very close to zero/one. When trying to recover the original value with get_value() machine imprecision leads to a completely wrong result.

To Reproduce

Quantity(10e9,min_val=0e9, max_val=10e30).get_value() will give 0

Expected behavior

Quantity(10e9,min_val=0e9, max_val=10e30).get_value() should return 10e9

Environment

• OS: ubuntu18
• Python Version: 3.8

[nwittler]

This is a precision error from applying a transform from physical range to [-1, 1]. It has not been working properly if you exactly hit the bound, too, so the corresponding methods (e.g.

c3/c3/c3objs.py

Line 256 in 5f20637

def set_value(self, val, extend_bounds=False) -> None:

) should be reworked. Till then, a workaround is to not set huge bounds.