Gnuplot

Gnuplot is a portable command-line graphing tool for Windows PCs and other platforms. The source code is copyrighted but freely released (meaning you don't have to pay for it). It was first designed to allow scientists and students to interactively visualize mathematical functions and data, but it has since expanded to serve a wide range of non-interactive applications, including web scripting. Third-party apps, such as Octave, also use it as a charting engine. It has been supported and actively developed since 1986. Gnuplot provides a wide range of 2D and 3D charts! 

It supports several different forms of output.

Interactive screen display options include cross-platform (Qt, wxWidgets, x11) and system-specific (MS Windows, OS/2). 

Output formats include postscript, pdf, png, gif, jpeg, LaTeX, Metafont, emf, and SVG. 

Mouseable online display types include HTML5 and SVG. 

What does Gnuplot offer?

• Two-dimensional functions and data plots can include a variety of components such as dots, lines, error bars, filled shapes, labels, arrows, etc. 
• Polar axes, log-scaled axes, general nonlinear axis mapping, and parametric coordinates Data visualizations include heat maps, beeswarm plots, violin plots, histograms, and so on. 
• 3D plots of data points, lines, and surfaces in various styles (contour plot, mesh) 
• Algebraic computation with integer, floating-point, or complex arithmetic. 
• Data-driven model fitting with Marquardt-Levenberg minimization. 
• Support for a wide range of operating systems, graphics file types, and output devices 
• Features include extensive online documentation and a TEX-like layout for labels, titles, axes, and data points. 
• Interactive command line editing and history 

The current development version will often include features not found in the most recent stable release of the gnu plot. As of April 2019, the 5.3 development version now supports 64-bit integer arithmetic. 

• 3D voxel grids. 
• 3D Plot Styles isosurface, circles, and boxes. 
• Set walls. Command to display xy, xz, and yz planes in 3D plots 
• Unicode escape sequences.U+hhhh Order N. Bessel functions of the first and second kind have been adjusted. Bessel functions support numerous textbox styles.