The Laplacian, or Laplace [[Operation|Operator]] of some [[Function]] $f(t)$ is the sum of second-order [[Derivative|partial derivatives]] of $f$ with respect to each spatial dimension ($x, y, z \in \R^{3}$). $\huge \nabla f' = \nabla ^{2}f = \pderiv{^{2}f}{x^{2}} +\pderiv{^{2}f}{y^{2}} +\pderiv{^{2}f}{z^2} $ Another definition is the [[Laplacian]] of a [[Function]] is the [[Divergence]] of its [[Gradient]].