GNU Octave - Scientific Programming Language

Powerful mathematics-oriented syntax with
built-in 2D/3D plotting and visualization tools

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Visualize data with high-level plot commands in
2D and 3D

x = -10:0.1:10; # Create an evenly-spaced vector from -10..10
y = sin (x);    # y is also a vector
plot (x, y);
title ("Simple 2-D Plot");
xlabel ("x");
ylabel ("sin (x)");