# harmean

harmonic mean : inverse of the inverses average (without zeros)

### Syntax

hm = harmean(x) hm = harmean(x, 'r'|1 ) hm = harmean(x, 'c'|2 )

### Arguments

- x
vector, matrix, or hypermatrix of real or complex numbers or polynomials. Rationals not supported.

- hm
scalar, or row (if

`"r"`

is used), or column (if`"c"`

is used). If`x`

are polynomials,`hm`

is of rational type.

### Description

This function computes the harmonic mean of input values = inverse of the average of inversed non-zero values.

`hm = harmean(x,'r')`

(or, equivalently,
`hm = harmean(x, 1)`

) returns in each entry of
the row vector `hm`

the harmonic mean of each
column of `x`

.

`hm = harmean(x,'c')`

(or, equivalently,
`hm = harmean(x, 2)`

) returns in each entry
of the column vector `hm`

the harmonic mean of
each row of `x`

.

If `x` is an hypermatrix and a
`"r", 1, "c", 2` flag is used, an error occurs. |

### Examples

harmean(1:10) // Returns 1 / mean(1 ./(1:10)) h = harmean([1 1 0 1 0 1]) // returns 1: zeros are not considered 1 / mean(1./[1 1 0 1 0 1]) // returns 0, as soon as a zero is present x = grand(3, 4, "uin",-10, 10) harmean(x) harmean(x, "r") harmean(x, 2) // Hypermatrix x = grand(3,4,2, "uin",-10, 10) harmean(x) harmean(x, "r") // error: not supported harmean(x, 3) // error: not supported harmean([%z 0]) harmean([%z %z/2]) harmean([%z %i+%z]) harmean([%z %i+%z]) == 1 / ((1/%z + 1/(%i+%z))/2)

### Bibliography

Wonacott, T.H. & Wonacott, R.J.; Introductory Statistics, fifth edition, J.Wiley & Sons, 1990.

## Comments

Add a comment:Please login to comment this page.