Creating a Heatmap

Overview

CZ ID includes a heatmap feature for visualizing taxa abundance across metagenomic samples. This guide describes steps to generate heatmaps using samples from the Feline Gingivostomatitis project.

Generating Heatmaps

To generate a heatmap:

1. Go to the Project page of interest and select the samples you want to compare by checking the boxes next to the sample name. If you want to select all samples in a project, click the checkbox in the upper left corner of the Sample Table.

2. Note that after sample selection you can see the number of selected samples and the heatmap icon.

1. Number of selected samples
2. Heatmap icon

3. Click the heatmap icon and select "Taxon Heatmap" from the dropdown menu.

4. The heatmap will automatically open in a new tab.

Displayed Taxa

By default, the generated heatmap displays the 10 species with the highest reads per million for each sample. You can adjust the displayed number of taxa per sample by adjusting the "Taxa per Sample" option found under the heamap filters (see image below). Note that it may take a few seconds for the heatmap to appear after changing settings. This is because heatmaps are generated from a large amount of data.

Adding Taxa

While the heatmap highlights the most abundant microbes in your samples, it may not capture all taxa of interest. For example, when searching for divergent viruses is important to be able to include low-abundance taxa in the heatmap. You can add any taxon that was found in at least one of your samples by using the “Add Taxon” button in the upper left corner of the heatmap (see image below). When you click "Add Taxon" a search box and a list of taxa will appear for you to find and select the taxon of interest, respectively.