# Completely rewritten parser supports

* Grouping with parentheses

* Noninteger powers of numbers (3^0.2)

* Functions (log, ln, log2, sin, cos, tan, exp) which operate on any dimensionless argument (e.g. log(watts/horsepower))

* Roots of units: sqrt(unit), cuberoot(unit), unit^(1|4), etc.

# Nonlinear units definitions can be specified in units.dat by giving functions that convert to and from linear units. This makes it possible to provide conversion between Fahrenheit and Celsius, one of the most requested features that is absent from version 1.55.

# Nonlinear units definitions can be specified by giving a list of points and using linear interpolation.