Unfortunately, there is no way to generate an analog graph from digital data in the software. The only way to visualize this information is to export the digital data—either the raw data using the main export feature found [here](Saving, Loading, and Exporting Data) or using the protocol export feature found [here](Using Protocol Analyzers).
It's definitely a good idea, and we've been thinking about it for a while. Ultimately, we would like to add math channel features as well as add support for protocol analyzers to produce analog graphs. However, we haven't put this on the road map yet.
trello ID: 55fae18c0c78301027d36f49
trello data: 14241308