​

function setup() {

  mycanvas = createCanvas(400, 400);

  tex = createP();

  tex.style('font-size', '20px');

  tex.position(130, 165);

  katex.render('\\nabla^{2}\\Phi=\\sigma(x)', tex.elt);

}

​

function draw() {

   noLoop();

   saveCanvas(mycanvas,"equation","png");

}