Modifying plots in PRIMER

Though PRIMER 7 does not attempt to replicate all the facilities available in graphics presentation software, there are a large number of graphics options available to modify dendrograms, many of them shared in a consistent interface for ordinations and other PRIMER plots. Note that the range of plots available now in PRIMER 7 has expanded greatly, with a new Plots menu and the concept of a multi-plot. This are discussed in Section 7 but examples can be seen scattered throughout this User Manual/Tutorial where they are relevant to a particular analytical technique. Some general features are that plots can be: resized; titles, sub-titles and axis titles edited, and font colours, sizes and types changed; these and the history display removed altogether; sample and variable labels replaced with factor levels and/or symbols, the latter having a choice of symbol size, type and colour; lines thickened (unselectively); axes rescaled to specification or even logged, though this will not usually be appropriate for a dendrogram, etc. New general features in PRIMER 7 include the ability with a single check box to change colour symbols or lines to monochrome and colour shading to mono hatching patterns, and much better control in plot keys of size of symbols and size, font and title font of text. Features specific to dendrograms include: the ability to orient the plot in any of the four directions; to display a slice through the tree at a fixed resemblance level, and create a factor (/indicator) that defines the groups at that threshold; to rotate sub-groups of the tree, in any permissible way; and to collapse the detail of specific sub-groups, so that the overall structure of a large tree can be better displayed. The fine detail is seen by another general facility for all plots in PRIMER: a flexible zoom operation which maintains the position of labelling and axis scaling while zooming in on the content of the plot. Importantly for dendro¬grams, the aspect ratio of the zoomed box can also be changed, allowing clear presentation of detailed structure (this latter feature does not operate with ordinations, for good reason – see later!).