"mass" - mkraska/meclib GitHub Wiki
[ "mass", "name", [x1, y1], r, off ]
black filled circle with label
"name"label, typeset in MathJax math mode[x1, y1]center positionr(optional, default: 4 pixel) radius of the circle in pixeloff(optional, default: 11 pixel) distance to text anchor of the label, in pixel
Example

[
[ "grid", "x","y", -5,5,-4,5, 50, [10,10], [0,0] ],
[ "mass", "name", [3, 2] ]
]