Sensitivity analysis giving incorrect values when a decision is isolated

[Miguel Ángel Artaso Landa]

Attached to the issue there are two networks. With the first one (ID-test-sens-an.pgmx), when performing a sensitivity analysis with the following scenario:

1. Open the attached network in Open Markov

2. Open the sensitivity analysis dialog (Tools -> Sensitivity analysis)

3. Configure the analysis desired as follows:

• Analysis type: Plot (one-way analysis)
• Points per parameter: 2 (the value can be any, but a lower value is better in this case)
• Parameter: prevalence (the only possible one in this network).
• Horizontal axis variation: user defined interval. from 0 to 1.
• Scope: Decision. Decision: D (the only possibility)

The lines in the plot are not parallel between each other. And they should as there is a tie in the policy.

When the decision is linked to an utility node with Uniform utility defined, the lines presented in the plot seem to be correct.

In any case, the inference is performed correctly.

[Miguel Ángel Artaso Landa]

The necessary changes have been implemented in the DeterministicSensitivityAnalysis class. Commit hash 0fb1514.