L = laplace(F) is the Laplace transform of the scalar F with default independent variable t.  If F is not a function of t, then F is  assumed to be a function of the independent variable returned by findsym(F,1).The default return is a function of s.

If F = F(s), then laplace returns a function of t.

By definition,

laplace(F,x) makes L a function of the variable x instead of the default s.

laplace(F,z,x) makes L a function of x instead of the default s. The integration is then with respect to z.

The laplace(M) function computes the element-wise Laplace transform of M.  The result, R, is formed as R[i,j] = laplace(M[i,j]).