Input and Output Interface

Main input file is in YAML file format. A set of autoconversion rules is applied in order to keep simple things simple while allowing complex inputs at the same time. Whole input structure is described by particular classes which provides automatically generated documentation (input reference) of the whole input structure. This structure more or less follows the structure of main program classes.

Almost all parameters in equations can be given as arbitrary space-time fields. There are several types of fields that differ in the way how they are represented on the input. Currently we support:

• constant field,
• constant field in space interpolated in time (can be defined in external CSV file),
• field given by a runtime parsed formula,
• field given by a Python code,
• element-wise constant field (given by VTK or GMSH file),
• element-wise constant field interpolated from different mesh data
  (given by VTK or GMSH file),
• field given by a native FE approximation of Flow123d
  (e.g. output of diff. Flow123d simulation).

Every input field can be specified in user-defined units, the set standard SI units is supported.

Any output field can be written either in VTK file format (XML ascii or XML binary) or in the GMSH file format version 2.