Graphviz is open source graph visualization software. Graph visualization is a way of representing structural information as diagrams of abstract graphs and networks. Visit https://graphviz.org for more information.
Graphviz can be used in Sympathy for Data to visualize profiling call graphs and decisiontrees for machinlearning models. To start using Graphviz, it must be installed and then configured. This is completely optional and necessary only to enable these visualizations.
For the call graph file to be generated Graphviz will have to be installed and the path to the bin folder which contains dot will have to be in either PATH or Graphviz install path, see Debug Preferences.