What is Graph?
Graph is an open source application used to draw mathematical graphs in a coordinate system. Anyone who wants to draw graphs of functions will find this program useful. The program makes it very easy to visualize a function and paste it into another program. It is also possible to do some mathematical calculations on the functions.
latest version is 4.4.2 (2013)https://sourceforge.net/projects/graph/files/Graph/
Comments and Reviews
Graph is the best program for quick analysis of functions and data. Allows you to visualize implicit functions, inequalities, graphically calculate integrals and derivatives. Allows you to approximate data by any user-defined function.
It is not as powerful as matlab but it can plot many functions and get you out of troubles very quickly