**
**OpenBUGS Graphics

Contents

General properties

Margins

Axis Bounds

Titles

All Plots

Fonts

Specific properties (via Special)

Density plot

Box plot

Caterpillar plot
__
__ Density strips

Model fit plot

Scatterplot

All OpenBUGS graphics have a set of basic properties that can be modified using the

Margins [top]

The

In cases where it is appropriate to alter a plot's margins the user may enter his/her preferred values and click on

Axis Bounds [top]

The user may specify new minimum and maximum values for either or both axes using the

Note that the resulting minima and maxima may not be exactly the same as the values specified because OpenBUGS always tries to ensure that axes range between 'nice' numbers and also have a sufficient number of tick marks. Note also that if max < min is specified then OpenBUGS will ignore it and the

(Some types of plot, such as trace plots, do not allow the user to change their axis bounds, because it would be inappropriate to do so.)

Titles [top]

The

Note, however, that because OpenBUGS does not (yet) support vertical text, a substantial amount of space may be required in the left margin in order to write the y-axis title horizontally - if sufficient space is not available then the y-axis title may not appear at all (clearly, this can be rectified by increasing the left margin).

All Plots [top]

The idea behind the

The user should first configure the focused plot in the desired way and then decide which of the plot's various properties are to be applied to all plots (of the same type, in the same window). The user should then check all relevant check-boxes and click on

Fonts [top]

The

First select the font to be modified and click on

In order to apply the same font to an arbitrarily large group of plots (not necessarily of the same type), rather than using the

Specific properties (via Special) [top]

Below we describe the special property editors that are available for certain types of plot. These allow user-interaction beyond that afforded by the standard tabs of the

Density plot [top]

When the

Property editor for histogram

Property editor for kernel density estimate

In either case, the

band-width = V

where the summations are from i = 1 to i = m. The default setting for s is 0.2.

Box plot [top]

The

Finally, at the bottom there is a colour field for selecting the fill-colour of the displayed boxes.

Caterpillar plot [top]

The

Density strips [top]

The

show baseline:

show labels:

log scale:

show 50% interval:

show 95% interval:

smooth:

If the data are discrete, then the bin size for the histogram is defined by the closest integer to the band-width implied by the supplied value of s, or 1 if this is greater. Smaller s give greater bin sizes, up to a maximum bin size equal to the closest integer to the standard deviation of the sample. Values of s closer to 1 give smaller bin sizes, up to a minimum bin size of 1, or of the closest integer to the standard deviation divided by the sample size if this is greater.

To update the plot after typing in a new smoothing parameter, click

Colour:

Model fit plot [top]

In cases where an axis is defined on a strictly positive range, it may be given a logarithmic scale by checking the appropriate check-box:

Scatterplot [top]

With a scatterplot focused, select the

Immediately beneath the

To the immediate right of the

s

where n is the number of scattered points and the summations are from j = 1 to j = n. The weights w

w

where s is the smoothing parameter defined in the