Metaboanalyst Heat Map Quantification

[jvanderroest]

Hello! I am making a heat map using metabolanalyst, and I am curious about how the heat map quantification is conducted. Here are the parameters that I’m using:

And here is an example heatmap that I’ve generated with those parameters:

How are the quantified values in the cells calculated? For example, the cell for “Low_Severity_0-5_cm_3” and “Ala-Pro-Pro-Pro” has a value of 4.85. How is that value calculated? Is it calculated through the “Autoscale Features” option for “Standardization?” What is the “Distance measure value” used for? Is it involved in calculating the cell values?

Thanks!

[jeff.xia]

These are very fundemental questions on heatmap. Overall, heatmaps are used for detecting overall patterns (high-low, similar-dissimilar). The exact values (such as 4.85) do not matter.

• How does the value computed? It really depends on your previous steps (processing, normalization, and scaling, etc).
• Distance measure does NOT affect the value. It is used to calculate how close (or similar) samples/features are to each other based on their value distributions.