Calculates the natural logarithm of the sum of field's value and 1. For small values x, the result of log1p(x) is much closer to the true result of ln(1 + x) than the floating-point evaluation of log(1.0+x)

asstringfalse_log1pThe name of the output field.
fieldstringtrue The name of the input field. [a]

[a] When you provide only one parameter, the implied parameter is field