Printing a Long Dendrogram

Pirouette can print most graphics in a WYSIWYG form, but the dendrogram represents a special case. If you have many samples, the default view may not be large enough to show the sample names on the leaf nodes. You can, of course, zoom in on a branch of the dendrogram that contains a small enough number of samples that the names will show, but that view will not show all samples. When you print, Pirouette understands that you would like the printed view to be just large enough that all sample names show. If this requires more than one page, cut marks are put on extra pages to indicate how the pages can be pasted together to form a single, continuous printed copy of the dendrogram. [Note: a current Pirouette bug prevents printing beyond the first page. This note serves as a workaround]

Many printing service bureaus now have printers that output to continuous roll paper. You can exploit this ability by making a file from Pirouette that can be printed on a single page with no need for pasting together multiple pages. This requires that you have installed on your computer Adobe Acrobat Distiller or that you have access to Distiller for some of the following steps.

The Method

First, display your dendrogram, moving the similarity cursor to an appropriate postion to indicate clusters. An example of such a dendrogram might look like this.


Next, do File > Print. In the Print dialog, choose the printer driver that will give the best output. If you don’t have a driver for a color printer, but do have Distiller installed, then select the Acrobat Distiller print driver as shown below.

choose distiller printer

Click on the Properties button, then click on the Advanced button as shown here.

printer properties

Among the options should be a choice of paper size. Select the custom paper size.

paper size option

Click on the Edit Custom Page size to present the following dialog.

custom page size definition

Modify the Height parameter to a size that you estimate to be large enough to fit the entire dendrogram. A rule of thumb for standard Pirouette settings is about 60 samples per page. Thus, you might try a Height of about 30 inches for a dendrogram containing 150 samples.

When you have finished, click OK to close each dialog. After dismissing the initial Print dialog, you will be asked to supply an Output File Name. The file will be written into the directory from which you loaded your data file.

file name

Distill this postscript file to a PDF with Distiller using your normal Distiller procedures. Open the resulting PDF file. The example shown earlier looks like this if you choose View > Fit in Window.

show dendrogram

If the file contains a large amount of white space below the graphic, as shown above, you can crop the image to a more appropriate size.

crop pages bounding box

Crop the margins to the Bounding Box.

final pdf picture

Then save the file. Your dendrogram is now ready for printing on a continuous feed printer.