In this exercise we will calculate the most probable sequence using a Dynamic Bayesian network.

Prerequisites

1 - Bayes Server

Bayes Server must be installed, before starting this walkthrough.

Note

An evaluation version can be downloaded from the Bayes Server website.

2 - The Bayesian network 'GCContent' available from the SampleNetworks folder, that is packaged with the course help.

Open the Bayesian network

  • Launch Bayes Server and open the Bayesian network GCContent.bayes located in the SampleNetworks folder, that is packaged with the course help.

Evidence

  1. Double click the Obs node. This will launch the Evidence window.

    Tip

    Data Explorer can also be used to set evidence from a database or spreadsheet.

  2. Enter the sequence GGCACTGAA, as shown in the image below.

    Exercise Most Probable Sequence Evidence

Add queries

  1. Click the + button on the GC Content node toolbar. This will launch the Series query window.

  2. Set the min time to 0, with a time type of Absolute.

  3. Set the max time to 0, with a time type of Relative.

    The Series Window should look like this.

    Exercise Most Probable Sequence Series Query
  4. Click Ok to add the queries for the Cluster node.

  5. Turn the Most Probable toggle button to on. This button is located on the Query tab of the main ribbon toolbar.

    The Bayesian network should look like this:

    Exercise Most Probable SequenceMPE
  6. Click the View Query node toolbar button on the GC Content node.

    This will launch the Query Distribution window, shown below:

    Tip

    Note that the probabilities do not sum to 1. This is expected behavior with Most Probable queries.

    Exercise Most Probable Sequence Query Distribution
  7. Confirm that the most probable sequence is HHHLLLLLL.