The mtaylor function computes a truncated multivariate Taylor series expansion of the input expression f, with respect to the variables v, to order n, using the variable weights w.

The variables v can be a list or set of names or equations. If  is an equation, then the left-hand side of  is the variable, and the right-hand side is the point of expansion.  If  is a name, then  is assumed as the point of expansion.

If the third argument n is present then it specifies the ``truncation order'' of the series. The concept of ``truncation order'' used is ``total degree'' in the variables. If n is not present, the truncation order used is the value of the global variable Order, which is 6 by default.

If the fourth argument w is present it specifies the variable weights to be used (by default all 1).  A weight of 2 will halve the order in the corresponding variable to which the series is computed.

Note:  mtaylor restricts its domain to ``pure'' Taylor series, those series with non-negative powers in the variables.