Summary:
Base 10 logarithm.

Syntax:
log10(expr)

Description:
Returns the base 10 logarithm of the numeric (float or double) expression expr (log₁₀(expr)). If expr does not evaluate to a float or a double, or if expr evaluates to a negative number, then log10(expr) returns an error.

Example:

...
variable: irrigation_level
  type: float
  definition:
    irrigation_level = log10(irrigated_surface)