The IsVectorField(v) command returns true if v is a vector field, that is if v was created by a call to the VectorField command, and false otherwise.

$\mathrm{with}\left(\mathrm{VectorCalculus}\right)\:$

$v≔\mathrm{VectorField}\left(⟨r^2\,\frac{\mathrm{\theta }}{r}⟩\,\mathrm{coordinates}=\mathrm{polar}\left[r,\mathrm{\theta }\right]\right)$

$v≔\left(r^2\right){\stackrel{\_}{e}}_r\+\left(\frac{\mathrm{\theta }}{r}\right){\stackrel{\_}{e}}_{\mathrm{\θ}}$

$\mathrm{IsVectorField}\left(v\right)$

$\mathrm{true}$