![Tangram-II](../../../images/title_tools_tangram2.gif)
![Modeling Environment](../../../images/title_sub_tools_tangram2_modeling.gif)
The TANGRAM-II modeling environment includes:
- Model Specification - The Model Specification Module allows the
user to define a model. The model is represented by a collection of objects,
which interact by sending and receiving messages. The internal state of
each object is represented by a set of integer or float valued variables. The model
is built using the TGIF tool.
- Generate the Mathematical Model - If all events in the model are
exponentially distributed, the Markov Chain is generated. TANGRAM-II can
also solve certain non-Markoviam models. In this case, the proper information
used by the solvers is generated..
- Mathematical Solution - In this case, the user can solve the model
analytically or the user can simulate the model. The Analytical Model Solution
Module implements several solution techniques for obtaining steady state
and transient behaviors. A technique to obtain the steady state solution
for a class of non-Markovian models is also implemented.
- Simulation - The TANGRAM-II simulator includes: Discrete events
simulation, in batch or interactive mode, and a rare event simulation module.
In the interactive mode the user can observe the evolution of the model
and construct animations.
- Measures of interest - The Measures of Interest Module allows the
user to compute a variety of measures of interest including: probability
mass function of state variables, probability of a set of states,
conditional probabilities. Furthermore, the user can specify measures in
the model specification environment using rewards. The results can be plotted
using GNUplot.
- Traffic Modeling - This module computes first and second order
statistics (traffic descriptors) from
Markovian models (fluid models) and from traces generated either by the
simulator or imported from a file.
![](../../../images/screen_modelenv.gif)