Driver

Background

The Driver.hpp file defines an instance to translate the JSON input's format file into Seismo-VLAB objects. In particular, components in the Geometry Module, Solution Module, and Input/Output Module provided in JSON format are transformed into objects.

The Driver main function are:

• RunDriverFile()
  which parse the domain file and then perform the analysis. This function calls internally:
  • UpdateMesh()
    which transform the json structure into recognizable objects defined at Geometry Module. Therefore Node, Material, Element, Fiber, Section, Load objects are created within this function.
  • UpdateAnalysis()
    which transform the json structure into recognizable objects defined at Solution Module. Therefore Algorithm, Integrator, LinearSystem, Analysis, objects are created within this function.
• Analysis::UpdateMesh()
  which performs modification in the model after an analysis is performed.

In SVL, we use RSJparser.hpp JSON parser, because it resembles the same structure used in python dictionaries. Below is a simple example (extracted from the RSJparser documentation) on how to use RSJparser in an implementation file:

std::string str = "{'RSJ': 'string data', 'keyName': [2,3,5,7]}";
RSJresource my_json(str);
std::cout  <<  my_json["keyName"][2].as<int>() << std::endl;     // prints 5
std::cout  <<  my_json["RSJ"].as<std::string>("default string") << std::endl; // prints "string data"
std::cout  <<  my_json["JSON"].as<std::string>("default string") << std::endl; // prints "default string"

The previous format is found extensively in the Driver.hpp which are mostly used in the UpdateMesh() and UpdateAnalysis() functions.

REFERENCE:

• Subhrajit Bhattacharya, "A Ridiculously Simple JSON Parser for C++", homepage https://www.lehigh.edu/~sub216/ or visit https://github.com/subh83/RSJp-cpp .