Data format of the TA Toolbox

All datasets get stored and processed in a unique and standardised format inside the TA Toolbox. That means that all routines of the toolbox expect to get data in this particular format. This page is used to document this format specification.

The TAload routine serves as an interface between all data formats that can be handled by the TA Toolbox and the GUI. Therefore, the TAload routine outputs the data structure specified here.

<note important>All fields defined here need to be filled with sensible values by each of the actual importer functions. The structures (Matlab™ structs) returned from the TAload routine are directly appended to the „data“ field of the GUI data.</note>

Background: During the development, it appeared to be sensible not only to store the actual data (strictly speaking, a n×m matrix), but a set of additional informations together with the data as well. Partly, these data can be derived from the raw data, partly they should be documented in the corresponding labbook. Having these informations in a data structure together with the actual data has several advantages, starting with having full access to this information from the GUI.

Given that there are plans for developing a “laboratory information system” storing finally all sorts of information about samples and measurements, collecting those “meta data” may well pay off at some point.

History

2012-10-22: Version 0.5
- New field “buffer” in “sample”
- New fields “experiment” and “purpose” in “parameters”
2012-04-14: Version 0.4
- New structure “timeProfiles” in “parameters”
2012-03-31: Version 0.3
- New structure “shotRepetitionRate” in “parameters”
2012-01-26: Version 0.2 (still)
- New field “background” in “parameters.probe”
2012-01-24: Version 0.2 (still)
- Changed format of “filter” in “parameters.probe”: previously struct, now string
2012-01-21: Version 0.2
- Added structure “aperture” in “parameters.spectrograph”
- Changed “parameters.date” in struct with fields “start” and “end”
- Added structure “spectrometer” with fields “name” and “software” in “parameters”
- Added structure “timeConstant” in “parameters.detection”
- Renamed field “opoDye” in “tunable”

Structure

Draft for the structure:

data - matrix
Actual data (without magnetic field)
dataMFon - matrix
Data acquired with magnetic field switched on (empty if no MFE setup used)
axes - struct
Additional information about the axes
- x - struct
  - values - vector
    Values of the x axis, same length as corresponding dimension of the data field
  - measure - string
    Measure
  - unit - string
    Unit
- y - struct
  - values - vector
    Values of the y axis, same length as corresponding dimension of the data field
  - measure - string
    Measure
  - unit - string
    Unit
- z - struct
  - measure - string
    Measure
  - unit - string
    Unit
parameters - struct
Additional informations about the measurement that get used oftenly
- runs - scalar
- operator - string
  Name of the user who recorded the dataset
- date - struct
  Start and end of the measurement
  - start - datetime
  - end - datetime
- NEW experiment - string
  Type of experiment performed (TA, MFE, MARY)
- NEW purpose - cell array
  Purpose of the experiment (free text)
- NEW shotRepetitionRate - struct
  Shot repetition rate of the experiment
  - value - scalar
  - unit - string
- spectrometer - struct
  Name and basic information about the setup used
  - name - string
    Short, comprehensive, unique identifier for the spectrometer
  - software - string
    Name and version of the software used for the measurement
- transient - struct
  - points - scalar
  - triggerPosition - scalar
  - length - scalar
  - unit - string
    Unit
- spectrograph - struct
  - type - string
    Type of the spectrograph used
  - model - string
    Actual spectrograph model used
  - NEW aperture - struct
    - front - struct
      - value - scalar
      - unit - string
    - back - struct
      - value - scalar
      - unit - string
- detection - struct
  - type - string
    Type of detection (“PMT”,“CCD”,…)
  - model - string
    Actual detector model used
  - powersupply - string
    Power supply of the detector
  - impedance - struct
    Resistance between PMT and recorder (therefore determining the time resolution)
    - value - scalar
    - unit - string
  - NEW timeConstant - struct
    Time constant (time resolution) of the detection (determined by the impedance)
    - value - scalar
    - unit - string
- recorder - struct
  - sensitivity - struct
    - value - scalar
    - unit - string
  - averages - scalar
  - timeBase - struct (old: scalar)
    - value - scalar
    - unit - string
  - bandwidth - struct
    - value - scalar
    - unit - string
  - coupling - string
    Type of coupling of the transient recorder (AC, DC, GND)
  - model - string
    Actual model of the transient recorder used
- pump - struct
  All informations regarding the pump beam
  - type - string
    Type of light source (“arclamp”,“laser”)
  - model - string
    Actual model of the light source used
  - wavelength - struct
    - value - scalar
    - unit - string
  - power - struct
    - value - scalar
    - unit - string
  - repetitionRate - struct
    - value - scalar
    - unit - string
  - tunable - struct
    - type - string
      Type of the device used (“OPO”,“dye”)
    - model - string
      Actual model of the used device
    - dye - string
      Name of the dye used (“none” in case of type=“OPO”)
- probe - struct
  All informations regarding the probe beam
  - type - string
    Type of the probe beam light source (“arclamp”,“laser”)
  - model - string
    Actual model of the light source used
  - wavelength - struct
    - start - scalar
    - stop - scalar
    - step - scalar
    - sequence - string
    - unit - string
  - power - struct
    - value - scalar
    - unit - string
  - filter - string
    List of filters used (can be more than one per time trace)
  - NEW background - string
- temperature - struct
  - value - scalar
  - unit - string
  - controller/model - string
    Actual model of the temperature controller
  - cryostat - string
    Actual model of the cryostat used (“none”, if none)
  - cryogen - string
    Cryogen used (“none”,“H2O”,“LN2”,“LHe”)
- MFE - struct
  All parameters regarding the MFE setup
  - field - struct
    - value - scalar
    - unit - string
      Unit
  - coils - struct
    - type - string
      Type of coils used (“Helmholtz”)
    - model - string
      Unique identifier for the coils used
  - powersupply - string
    Power supply for the coils
  - gaussmeter - string
- NEW timeProfiles - struct (1xn)
  - filename - string
  - wavelength - struct
    - value - scalar
    - unit - string
  - averages - scalar
  - runs - scalar
  - filter - string
sample - struct
Details of the sample¹⁾
- name - string
  (unique), short and comprehensive name of the sample
- description - cell array
  Description of the sample (free text)
- NEW buffer - cell array
  Description of the buffer used (free text)
- preparation - cell array
  Description of sample preparation (free text)
- cuvette - string
  cell/cuvette used
header - cell array
Comment header of the file read
comment - cell array
Comment to the measurement (free text)
info - struct
Additional information about the dataset, e.g. to the sample. Ideally, key-value pairs; empty if not available.
file - struct
- name - string
  File name, with complete or relative path, where applicable
- format - string
  File format²⁾
label - string
Name that is used for display, e.g. in the TAgui; empty string if not available
format - struct
Informations regarding the data structure/format
- name - string
  Name of the data structure/format: “TA toolbox”; used for identification
- version - string
  Version number of the data structure

¹⁾

Later on, additional fields can be easily added here. Therefore, the description currently just goes into a cell array.

²⁾

Best to use here the same format identifiers that are use in the TAload.ini file