NAG Library Routine Document

g01arf  (plot_stem_leaf)

1

Purpose

2

Specification

3

Description

1  1  8
3  1  99
5  2  00
5  2  111
2  2
2  2  3
1  2  4

 1   1.  9
 1   1*
 1  -0.
 3  -0*  13
15  +0*  012233344444
15  +0.  55556667788
 5   1*  011
 2   1.  3
 1   2
 1   2.
 1   3   1

      LO   -19

  2   -0*  3
  3   +0T  1
  5   +0*  01
 10   +0T  22333
( 9)  +0F  444445555
 11   +0*  66677
  6   +0T  8
  5    1*  011
  2    1T  3

      HI   31

4

References

5

Arguments

1:     $\mathbf{range}$ – Character(1)Input

On entry: indicates whether you wish to scale the plot to the extremes of the data or to the fences.

$\mathbf{range}=\text{'E'}$

The display is a plot to the extremes, that is a plot of all the data.

$\mathbf{range}=\text{'F'}$

The display is a plot of the data between the fences.

Constraint: $\mathbf{range}=\text{'E'}$ or $\text{'F'}$.

2:     $\mathbf{prt}$ – Character(1)Input

On entry: indicates whether the stem and leaf display is to be output to an external file.

$\mathbf{prt}=\text{'N'}$

The display is not output to an external file.

$\mathbf{prt}=\text{'P'}$

The display is output to the current advisory message unit as defined by x04abf. Only the first $132$ characters of each line are actually printed.

Constraint: $\mathbf{prt}=\text{'P'}$ or $\text{'N'}$.

3:     $\mathbf{n}$ – IntegerInput

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

Constraint: $\mathbf{n}\ge 2$.

4:     $\mathbf{y}\left(\mathbf{n}\right)$ – Real (Kind=nag_wp) arrayInput

On entry: the $n$ observations.

5:     $\mathbf{nstepx}$ – IntegerInput

On entry: the number of character positions to be plotted horizontally.

Constraint: $\mathbf{nstepx}\ge 35$.

6:     $\mathbf{nstepy}$ – IntegerInput

On entry: the maximum number of character positions to be plotted vertically.

If $\mathbf{nstepy}\le 0$ a suitable value will be used by g01arf for the number of character positions to be plotted vertically. This will clearly be less than or equal to the value of ldplot.

Constraint: $\mathbf{nstepy}\le 0$ or $\mathbf{nstepy}\ge 5$.

7:     $\mathbf{unit}$ – Real (Kind=nag_wp)Input/Output

On entry: indicates the leaf digit unit to be used.

If $\mathbf{unit}>0.0$ and is not a power of ten, it will be converted to the nearest power of ten below the input value for unit.

If $\mathbf{unit}\le 0.0$, the optimum unit will be used. This is based on the range of the data to be plotted and the number of lines available for the display.

On exit: contains the actual unit used in the stem and leaf display.

8:     $\mathbf{plot}\left(\mathbf{ldplot},\mathbf{nstepx}\right)$ – Character(1) arrayOutput

On exit: the stem and leaf display.

9:     $\mathbf{ldplot}$ – IntegerInput

On entry: the first dimension of the array plot as declared in the (sub)program from which g01arf is called.

Constraint: $\mathbf{ldplot}\ge \max \left(5,\mathbf{nstepy}\right)$.

10:   $\mathbf{lines}$ – IntegerOutput

On exit: the actual number of lines needed for the display.

11:   $\mathbf{sorty}\left(\mathbf{n}\right)$ – Real (Kind=nag_wp) arrayOutput

On exit: the observations sorted into ascending order.

12:   $\mathbf{iwork}\left(\mathbf{n}\right)$ – Integer arrayWorkspace

13:   $\mathbf{ifail}$ – IntegerInput/Output

On entry: ifail must be set to $0$, $-1\text{ or }1$. If you are unfamiliar with this argument you should refer to Section 3.4 in How to Use the NAG Library and its Documentation for details.

For environments where it might be inappropriate to halt program execution when an error is detected, the value $-1\text{ or }1$ is recommended. If the output of error messages is undesirable, then the value $1$ is recommended. Otherwise, if you are not familiar with this argument, the recommended value is $0$. When the value $-\mathbf{1}\text{ or }\mathbf{1}$ is used it is essential to test the value of ifail on exit.

On exit: $\mathbf{ifail}=\mathbf{0}$ unless the routine detects an error or a warning has been flagged (see Section 6).

6

Error Indicators and Warnings

$\mathbf{ifail}=1$

On entry, $\mathbf{ldplot}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ldplot}\ge 5$.

On entry, $\mathbf{ldplot}=〈\mathit{\text{value}}〉$ and $\mathbf{nstepy}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{ldplot}\ge \mathbf{nstepy}$.

On entry, $\mathbf{n}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{n}\ge 2$.

On entry, $\mathbf{nstepx}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{nstepx}\ge 35$.

On entry, $\mathbf{nstepy}>0$ and $\mathbf{nstepy}<5$: $\mathbf{nstepy}=〈\mathit{\text{value}}〉$.

$\mathbf{ifail}=2$

On entry, $\mathbf{prt}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{prt}=\text{'P'}$ or $\text{'N'}$.

On entry, $\mathbf{range}=〈\mathit{\text{value}}〉$.
Constraint: $\mathbf{range}=\text{'E'}$ or $\text{'F'}$.

$\mathbf{ifail}=3$

Lines needed for display ($〈\mathit{\text{value}}〉$) exceed nstepy ($〈\mathit{\text{value}}〉$).

$\mathbf{ifail}=4$

A value exceeds maximum allowed for an integer.

$\mathbf{ifail}=-99$

An unexpected error has been triggered by this routine. Please contact NAG.

See Section 3.9 in How to Use the NAG Library and its Documentation for further information.

$\mathbf{ifail}=-399$

Your licence key may have expired or may not have been installed correctly.

See Section 3.8 in How to Use the NAG Library and its Documentation for further information.

$\mathbf{ifail}=-999$

Dynamic memory allocation failed.

See Section 3.7 in How to Use the NAG Library and its Documentation for further information.

7

Accuracy

8

Parallelism and Performance

9

Further Comments

10

Example

10.1

Program Text

Program Text (g01arfe.f90)

10.2

Program Data

Program Data (g01arfe.d)

10.3

Program Results

Program Results (g01arfe.r)