NAG C Library Function Document

nag_median_1var (g07dac)

1

Purpose

2

Specification

3

Description

4

References

5

Arguments

1:    $\mathbf{n}$ – IntegerInput

On entry: the number of observations, $n$.

Constraint: $\mathbf{n}>1$.

2:    $\mathbf{x}\left[\mathbf{n}\right]$ – const doubleInput

On entry: the vector of observations, $x_1,x_2,\dots ,x_n$.

3:    $\mathbf{y}\left[\mathbf{n}\right]$ – doubleOutput

On exit: the observations sorted into ascending order.

4:    $\mathbf{xme}$ – double *Output

On exit: the median, ${\theta }_{\mathrm{med}}$.

5:    $\mathbf{xmd}$ – double *Output

On exit: the median absolute deviation, ${\sigma }_{\mathrm{med}}$.

6:    $\mathbf{xsd}$ – double *Output

On exit: the robust estimate of the standard deviation, ${\sigma }_{\mathrm{med}}^{\prime }$.

7:    $\mathbf{fail}$ – NagError *Input/Output

The NAG error argument (see Section 3.7 in How to Use the NAG Library and its Documentation).

6

Error Indicators and Warnings

NE_INT_ARG_GT

On entry, $\mathbf{n}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{n}\le 〈\mathit{\text{value}}〉$.

NE_INT_ARG_LE

On entry, $\mathbf{n}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{n}>1$.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (g07dace.c)

10.2

Program Data

Program Data (g07dace.d)

10.3

Program Results

Program Results (g07dace.r)