# ExpScale¶

class ExpScale(a=2.718281828459045, b=1, c=1, inverse=False)[source]

Bases: _Scale, ScaleBase

“Exponential scale” that performs either of two transformations. When inverse is False (the default), performs the transformation

$Ca^{bx}$

where the constants $$a$$, $$b$$, and $$C$$ are set by the input (see below). When inverse is True, this performs the inverse transformation

$(\log_a(x) - \log_a(C))/b$

which in appearance is equivalent to LogScale since it is just a linear transformation of the logarithm.

Parameters
• a (float, optional) – The base of the exponential, i.e. the $$a$$ in $$Ca^{bx}$$.

• b (float, optional) – The scale for the exponent, i.e. the $$b$$ in $$Ca^{bx}$$.

• c (float, optional) – The coefficient of the exponential, i.e. the $$C$$ in $$Ca^{bx}$$.

• inverse (bool, optional) – If True, the “forward” direction performs the inverse operation.

Methods Summary

 limit_range_for_scale(vmin, vmax, minpos) Return the range vmin and vmax limited to positive numbers.