HARMEAN Function

If any argument is negative, then the result is a null or missing value. A message appears in the log that the negative argument is invalid. If all the arguments are null or missing values, then the result is a null or missing value. Otherwise, the result is the harmonic mean of the non-null or nonmissing values.

If any argument is zero, then the harmonic mean is zero. Otherwise, the harmonic mean is the reciprocal of the arithmetic mean of the reciprocals of the values.

Let be the number of arguments with non-null or nonmissing values, and let be the values of those arguments. The harmonic mean is shown in this equation.

Floating-point arithmetic often produces tiny numerical errors. Some computations that result in zero when exact arithmetic is used might result in a tiny nonzero value when floating-point arithmetic is used. Therefore, HARMEAN fuzzes the values of arguments that are approximately zero. When the value of one argument is extremely small relative to the largest argument, the former argument is treated as zero. If you do not want SAS to fuzz the extremely small values, then use the HARMEANZ function.