Functions and CALL Routines |
Returns the harmonic mean.
Category: |
Descriptive Statistics
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HARMEAN(argument<,argument,...>)
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argument
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is a non-negative numeric constant, variable,
or expression.
Tip: |
The argument list can consist
of a variable list, which is preceded by OF. |
The MEAN function returns the arithmetic
mean (average), and the GEOMEAN function returns the geometric mean, whereas
the HARMEAN function returns the harmonic mean of the non-missing values.
Unlike HARMEANZ, HARMEAN fuzzes the values of the arguments that are approximately
zero.
If any argument is negative, then the
result is a missing value. A message appears in the log that the negative
argument is invalid, and _ERROR_ is set to 1. If all the arguments are missing
values, then the result is a missing value. Otherwise, the result is the harmonic
mean of the non-missing 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-missing values, and
let
be the values of those arguments. The harmonic mean is
Floating-point arithmetic often produces tiny numerical
errors. Some computations that result in zero when exact arithmetic is used
might result in a tiny non-zero 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, then the former argument is treated as zero. If you do not want
SAS to fuzz the extremely small values, then use the HARMEANZ function.
SAS Statements |
Results |
x1=harmean(1,2,4,4);
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2
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x2=harmean(.,4,12,24);
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8
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x3=harmean(of x1-x2);
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3.2
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Copyright © 2011 by SAS Institute Inc., Cary, NC, USA. All rights reserved.