Documentation


Interface

SDAPS is a command line application. After building the C extension and documentation (and optionally installing it into the system) you can execute it.

  • Run 'sdaps' if you installed it
  • Run './sdaps.py' from the source directory otherwise.

With --help you can get a list of commands. To get more information about one of these commands run SDAPS with sdaps X command --help. The X can be any string, it just needs to be there as SDAPS expects a path to a project directory.

Important Commands

  • setup or setup_tex: Creates a new project directory for the given questionnaire
  • stamp: Create printable PDF
  • add: Adds scanned image data. From version 1.1.7 onwards SDAPS will automatically convert files to the appropriate format if the --convert option is given. Only use this option if the scan is not already in the appropriate format for SDAPS (monochrome multipage tiff). See also Scanning.
  • recognize: Runs the optical mark recognition
  • reorder: Group pages using their (unique) questionnaire ID. (ie. fix order after pages have been mixed up)
  • gui: Starts a graphical user interface that can be used to correct errors in the automatic recognition.
  • report (and report_tex): Creates a report of the results as PDF.
  • csv: Can be used to export the data to a CSV file.

Filtering

Some commands can work only on a subset of the data (eg. report, csv export). With this it is possible to create a PDF report that is for example separated by the sex of the participant. These filters are python logic expressions.

For the logic expression, every choice question is exported as a list of checked boxes. The list of boxes is zero based and freeform fields are included. The mark type question is instead exported as a number between 0 and 5, where zero means "no answer".

As these are python expressions, you can simply combine them with and and or. It is allowed to combine such a filter with the --all-filters argument that the report script has.

Example filter:

  • 0 in _1_2: First checkbox of question 1.2 is checked (others of the same question may be checked too).
  • _1_2 == [0]: Only the first checkbox of question 1.2 is checked.
  • _2_1 == 1: Question 2.1 is a mark question, and the leftmost box has been checked.
  • _2_1 == 0: Question 2.1 is a mark question, and is not valid (no box, or multiple checked boxes).

Other variables that can be queried:

  • survey_id: The survey ID (will always be the correct one)
  • questionnaire_id: The questionnaire ID if a barcode was found.
  • global_id: The global ID if a barcode was found.
  • valid: Whether the sheet is considered valid (ie. no fatal errors).
  • quality: The estimated quality of the recognition (a value between 0 and 1).
  • recognized: Whether recognition has been run for the sheet. (new since 1.1.1)
  • verified: Whether a verifier has acknowledged the sheet. (new since 1.1.1)
  • complete: Whether all pages are scanned and could be identified for the sheet. (new since 1.1.2)

Example call of the "report" command:

$ sdaps some_project report --filter "(0 in _1_2 or _2_1 == 1) and global_id=='some name'"

SDAPS Project Directory

SDAPS creates a project directory for every survey you create. This directory is used to store all the data that belongs to the survey. Some special files:

  • info: A file containing metadata, this may be modified directly.
  • survey: Data storage (pickled python objects)
  • *.tif: The scanned images that have been added to the project

It is also used as the default output directory for commands that create new files.

More documentation

Have a look at the links in the menu. Quite a lot is not yet documented. There are some notes about this in Documentation/Missing.