Power Law with Offsets
A power law shifted along both axes. Use it when a power-law dependence starts at a threshold xₒ and sits on a constant background.
Parameters
- Scale factor.
- Horizontal offset: where the power-law term is zero, for positive B.
- Exponent.
- Vertical offset: the value of y at x = xₒ, for positive B.
Tips
- x − xₒ must be positive when B can take non-integer values. If the fit fails, enter a guess for xₒ just below your smallest x.
- Offsets on both axes can be hard to separate from A and B. Fix xₒ or C if you know it.
- With xₒ fixed at 0, this is Power Law with Vertical Offset.