Scilab

Scilab is free and open source software for numerical computation providing a powerful computing environment for engineering and scientific applications. Scilab includes hundreds of mathematical functions. It has a high level programming language allowing access to advanced data structures, 2-D and 3-D graphical functions. A large number of functionalities is included in Scilab:

Maths & Simulation: For usual engineering and science applications

2-D & 3-D Visualization: Graphics functions to visualize, annotate and export data

Optimization: Algorithms to solve constrained and unconstrained continuous and discrete problems

Statistics: Tools to perform data analysis and modeling

Control System Design & Analysis: Standard algorithms and tools for control system study

Signal Processing: Visualize, analyze and filter signals in time and frequency domains