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LogLikelihood

LogLikelihood defines the objective terms evaluated for each sampled point.

It appears under the Sampling block and is shared by samplers that need a likelihood or score value.

Minimal form

Sampling:
  LogLikelihood:
    - name: L_total
      expression: "-0.5 * chi2"

Each entry contains:

  • name: stable name for the likelihood term.
  • expression: symbolic expression evaluated after scan variables and workflow outputs are available.

Multiple terms

Use multiple entries when you want to keep contributions inspectable:

Sampling:
  LogLikelihood:
    - name: L_higgs
      expression: "-0.5 * chi2_higgs"
    - name: L_flavor
      expression: "-0.5 * chi2_flavor"
    - name: L_total
      expression: "L_higgs + L_flavor"

Keep the final combined term explicitly named when downstream analysis expects a single likelihood column.

Expression inputs

Likelihood expressions can use:

  • scan variables from Sampling.Variables
  • calculator or opera outputs mapped into the sample record
  • derived symbolic quantities documented in Symbolic Expressions