The Asimov Ledger¶

The ledger is the central source of information within a project, and stores information about events and analyses.

Data in the ledger is hierarchical, so settings can be specified on a per-project, per-event, and per-analysis level, allowing project-wide defaults to be set, but overwritten when required. In addition defaults can be set for each pipeline.

In this documentation we’ll represent the ledger in yaml format, however a number of other storage methods for the ledger are also supported by asimov.

The ledger hierarchy¶

Project data¶

The project is the top level of the hierarchy within asimov. Settings which are defined for the project are passed to all events and those events’ analyses.

Event data¶

Events are stored under the events key of the ledger. All events are attached to a project, and they inherit all of the settings from their project.

Analysis data¶

All analyses are attached to an event, and inherit all of the settings from their event.

Pipeline data¶

In addition to specifying project or event defaults, it is possible to define per-pipeline defaults in the pipelines key of the ledger, which are only used by a specific pipeline. For example, you may wish to specify a different set of defaults for all bilby analyses compared to all rift analyses.

Applying changes to the ledger¶

There are a number of ways that changes can be applied to the ledger, for example adding new analyses, new events, or setting defaults.

Via the command line interface
By writing a ledger page and adding it to the ledger
By directly editing the ledger

The first two options are the recommended approach for the vast majority of situations. While editing the ledger directly is the most powerful approach it also presents more risks.

Detector information¶

Information about which detectors should be used for an analysis is contained under the interferometers key.

This should be a list of detector abbreviations, for example [H1, L1, V1].

Examples¶

In order to provide the IFO list for all analyses in a given event:

- name: GW150915
  interferometers:
  - L1
  - H1
  productions:
    Prod1: ...

Data information¶

Information and settings about the data are stored under the data key.

Examples¶

data:
  calibration:
    H1: h1-calibration.dat
    L1: l1-calibration.dat
 channels:
   H1: H1:DCS-CALIB_STRAIN_C02
   L1: L1:DCS-CALIB_STRAIN_C02
 frame-types:
   H1: H1_HOFT_C02
   L1: L1_HOFT_C02
 segments:
   H1: H1:DMT-ANALYSIS_READY:1
   L1: L1:DMT-ANALYSIS_READY:1
 segment length: 4

calibration

This section defines the location of the calibration splines for the analysis. These can either be specified relative to the event repository, or as an absolute path. Files should be provided for each detector, indexed by the detector abbreviation.

For example

data:
  calibration:
    H1: /home/cal/H1-calibration.dat
    V1: /home/cal/V1-calibration.dat

channels

This section defines the data channels which should be used in the analysis. These should be provided for each detector. For example

data:
  channels:
    H1: H1:DCS-CALIB_STRAIN_C02
    L1: L1:DCS-CALIB_STRAIN_C02

frame-types

This section defines the frame types which should be used in the analysis. These should be provided for each detector. For example

data:
  frame-types:
    H1: H1_HOFT_C02
    L1: L1_HOFT_C02

segments

This section defines the segments which should be used in the analysis. These should be provided for each detector. For example

data:
  segments:
    H1: H1:DMT-ANALYSIS_READY:1
    L1: L1:DMT-ANALYSIS_READY:1

data files

This section should define data files which contain the analysis data to be used in the analysis, and should be provided for each detector. For example

data:
  data files:
    H1: ./H1-file.gwf
    L1: ./L1-file.gwf

Data quality information¶

Examples¶

quality:
  minimum frequency:
    H1: 20
    L1: 20
  maximum frequency:
    H1: 2048
    L1: 2048

Likelihood settings¶

Examples¶

likelihood:

  psd length: 4
  reference frequency: 20
  sample rate: 2048
  segment start: 1126259460.391
  start frequency: 13.333333333333334
  window length: 4

Sampler settings¶

Examples¶

Prior settings¶

Examples¶

priors:
  chirp mass:
    type: UniformInComponentsChirpMass
    minimum: 0
    maximum: 100
  mass ratio:
    type: UniformInComponentsMassRatio
    minimum: 0.1
    maximum: 1.0
  mass 1:
    type: Constraint
    minimum: 0
    maximum: 1
  mass 2:
    type: Constraint
    minimum: 0
    maximum: 1
  spin 1:
    type: Uniform
    minimum: 0
    maximum: 1
  spin 2:
    type: Uniform
    minimum: 0
    maximum: 1
  tilt 1:
    type: Sine
  tilt 2:
    type: Sine
  phi 12:
    type: Uniform
  phi jl:
    type: Uniform
  luminosity distance:
    type: PowerLaw
    minimum: 0
    maximum: 1000
    alpha: 2
  dec:
    type: Cosine
  ra:
    type: Uniform
  theta jn:
    type: Sine
  psi:
    type: Uniform
  phase:
    type: Uniform
    boundary: periodic